The Experts below are selected from a list of 168491076 Experts worldwide ranked by ideXlab platform
Volker Gerke - One of the best experts on this subject based on the ideXlab platform.
-
N-terminal acetylation of annexin A2 is required for S100A10 binding.
Biological Chemistry, 2012Co-Authors: Ali Reza Nazmi, Volker Gerke, Gabriel Ozorowski, Milena Pejic, Julian P. Whitelegge, Hartmut LueckeAbstract:Annexin A2 (AnxA2), a Ca2+-regulated phospholipid binding protein involved in membrane-cytoskeleton contacts and membrane transport, exists in two physical states, as a monomer or in a heterotetrameric complex mediated by S100A10. Formation of the AnxA2-S100A10 complex is of crucial regulatory importance because only the complex is firmly anchored in the plasma membrane, where it functions in the plasma membrane targeting/recruitment of certain ion channels and receptors. The S100A10 binding motif is located in the first 12 residues of the AnxA2 N-terminal domain, but conflicting reports exist as to the importance of N-terminal AnxA2 acetylation with regard to S100A10 binding. We show here that AnxA2 is subject to N-terminal modification when expressed heterologously in Escherichia coli. Met1 is removed and Ser2 is acetylated, yielding the same modification as the authentic mammalian protein. Bacterially expressed and N-terminally acetylated AnxA2 binds S100A10 with an affinity comparable to AnxA2 from porcine tissue and is capable of forming the AnxA2-S100A10 heterotetramer. Complex formation is competitively inhibited by acetylated but not by non-acetylated peptides covering the N-terminal AnxA2 sequence. These results demonstrate that N-terminal acetylation of AnxA2 is required for S100A10 binding and that this common eukaryotic modification is also obtained upon expression in bacteria.
-
the annexin 2 S100A10 complex and its association with trpv6 is regulated by camp pka cna in airway and gut epithelia
Cell Calcium, 2008Co-Authors: Lee A Borthwick, Volker Gerke, Andy Neal, Lynsey Hobson, L Robson, Richmond MuimoAbstract:Summary The formation of a heterotetrameric complex between annexin 2 (anx 2) and S100A10 plays an important role in regulating the cellular distribution and biochemical properties of anx 2. A major distinction between the anx 2-S100A10 complex and other annexin-S100 complexes is that S100A10 binding to anx 2 occurs independently of calcium. Here we describe a cyclic 3′,5′-adenosine monophosphate (cAMP) and cAMP-dependent protein kinase (PKA, EC 2.7.1.37)-dependent mechanism regulating anx 2-S100A10 complex formation and its interaction with the transient receptor potential vanilloid type 6 channel (TRPV6) in airway and gut epithelia. In both 16HBE14o- and Caco-2 cells, forskolin (FSK) stimulated increased anx 2-S100A10 complex formation, which was attenuated by either PKA inhibitors or calcineurin A (CnA) inhibitors. The anx 2-S100A10 complex association with TRPV6 was dependent on FSK-induced CnA-dependent dephosphorylation of anx 2. Analysis of the significance of the cAMP/PKA/CnA pathway on calcium influx showed that both PKA and CnA inhibitors attenuated Ca45 uptake in Caco-2, but not 16HBE14o-, cells. Thus, the cAMP/PKA/CnA-induced anx 2-S100A10/TRPV6 complex may require additional factors for calcium influx or play a role independent of calcium influx in airway epithelia. In conclusion, our data demonstrates that cAMP/PKA/CnA signalling is important for anx 2-S100A10 complex formation and interaction with target molecules in both absorptive and secretory epithelia.
-
The annexin 2-S100A10 complex and its association with TRPV6 is regulated by cAMP/PKA/CnA in airway and gut epithelia.
Cell Calcium, 2008Co-Authors: Lee A Borthwick, Volker Gerke, Andy Neal, Lynsey Hobson, L Robson, Richmond MuimoAbstract:The formation of a heterotetrameric complex between annexin 2 (anx 2) and S100A10 plays an important role in regulating the cellular distribution and biochemical properties of anx 2. A major distinction between the anx 2-S100A10 complex and other annexin-S100 complexes is that S100A10 binding to anx 2 occurs independently of calcium. Here we describe a cyclic 3',5'-adenosine monophosphate (cAMP) and cAMP-dependent protein kinase (PKA, EC 2.7.1.37)-dependent mechanism regulating anx 2-S100A10 complex formation and its interaction with the transient receptor potential vanilloid type 6 channel (TRPV6) in airway and gut epithelia. In both 16HBE14o- and Caco-2 cells, forskolin (FSK) stimulated increased anx 2-S100A10 complex formation, which was attenuated by either PKA inhibitors or calcineurin A (CnA) inhibitors. The anx 2-S100A10 complex association with TRPV6 was dependent on FSK-induced CnA-dependent dephosphorylation of anx 2. Analysis of the significance of the cAMP/PKA/CnA pathway on calcium influx showed that both PKA and CnA inhibitors attenuated Ca(45) uptake in Caco-2, but not 16HBE14o-, cells. Thus, the cAMP/PKA/CnA-induced anx 2-S100A10/TRPV6 complex may require additional factors for calcium influx or play a role independent of calcium influx in airway epithelia. In conclusion, our data demonstrates that cAMP/PKA/CnA signalling is important for anx 2-S100A10 complex formation and interaction with target molecules in both absorptive and secretory epithelia.
-
S100A10/p11: family, friends and functions
Pflügers Archiv - European Journal of Physiology, 2008Co-Authors: Ursula Rescher, Volker GerkeAbstract:S100A10, also known as p11 or annexin 2 light chain, is a member of the S100 family of small, dimeric EF hand-type Ca^2+-binding proteins that generally modulate cellular target proteins in response to intracellular Ca^2+ signals. In contrast to all other S100 proteins, S100A10 is Ca^2+ insensitive because of amino acid replacements in its Ca^2+-binding loops that lock the protein in a permanently active state. Within cells, the majority of S100A10 resides in a tight heterotetrameric complex with the peripheral membrane-binding protein annexin A2 that directs the complex to specific target membranes, in particular the plasma membrane and the membrane of early endosomes. Several other Ca^2+-independent interaction partners of S100A10 have been described in the recent past. Many of these interactions, which have been shown to be of functional significance for the respective partner, involve plasma membrane-resident proteins. In most of these cases, S100A10, probably residing in a complex with annexin A2, appears to regulate the intracellular trafficking of the respective target protein and thus its functional expression at the cell surface. In this paper, we review the current information on S100A10 protein interactions placing a particular emphasis on data that contribute to an understanding of the mechanistic basis of the S100A10 action. Based on these data, we propose that S100A10 functions as a linker tethering certain transmembrane proteins to annexin A2 thereby assisting their traffic to the plasma membrane and/or their firm anchorage at certain membrane sites.
-
the formation of the camp protein kinase a dependent annexin 2 S100A10 complex with cystic fibrosis conductance regulator protein cftr regulates cftr channel function
Molecular Biology of the Cell, 2007Co-Authors: Lee A Borthwick, Volker Gerke, L Robson, Jean Mcgaw, Gregory E. Conner, Christopher J. Taylor, Anil Mehta, Richmond MuimoAbstract:Cystic fibrosis results from mutations in the cystic fibrosis conductance regulator protein (CFTR), a cAMP/protein kinase A (PKA) and ATP-regulated Cl− channel. CFTR is increasingly recognized as a component of multiprotein complexes and although several inhibitory proteins to CFTR have been identified, protein complexes that stimulate CFTR function remain less well characterized. We report that annexin 2 (anx 2)–S100A10 forms a functional cAMP/PKA/calcineurin (CaN)-dependent complex with CFTR. Cell stimulation with forskolin/3-isobutyl-1-methylxanthine significantly increases the amount of anx 2–S100A10 that reciprocally coimmunoprecipitates with cell surface CFTR and calyculin A. Preinhibition with PKA or CaN inhibitors attenuates the interaction. Furthermore, we find that the acetylated peptide (STVHEILCKLSLEG, Ac1-14), but not the nonacetylated equivalent N1-14, corresponding to the S100A10 binding site on anx 2, disrupts the anx 2–S100A10/CFTR complex. Analysis of 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS) and CFTRinh172-sensitive currents, taken as indication of the outwardly rectifying Cl− channels (ORCC) and CFTR-mediated currents, respectively, showed that Ac1-14, but not N1-14, inhibits both the cAMP/PKA-dependent ORCC and CFTR activities. CaN inhibitors (cypermethrin, cyclosporin A) discriminated between ORCC/CFTR by inhibiting the CFTRinh172-, but not the DIDS-sensitive currents, by >70%. Furthermore, peptide Ac1-14 inhibited acetylcholine-induced short-circuit current measured across a sheet of intact intestinal biopsy. Our data suggests that the anx 2–S100A10/CFTR complex is important for CFTR function across epithelia.
Ursula Rescher - One of the best experts on this subject based on the ideXlab platform.
-
S100A10/p11: family, friends and functions
Pflügers Archiv - European Journal of Physiology, 2008Co-Authors: Ursula Rescher, Volker GerkeAbstract:S100A10, also known as p11 or annexin 2 light chain, is a member of the S100 family of small, dimeric EF hand-type Ca^2+-binding proteins that generally modulate cellular target proteins in response to intracellular Ca^2+ signals. In contrast to all other S100 proteins, S100A10 is Ca^2+ insensitive because of amino acid replacements in its Ca^2+-binding loops that lock the protein in a permanently active state. Within cells, the majority of S100A10 resides in a tight heterotetrameric complex with the peripheral membrane-binding protein annexin A2 that directs the complex to specific target membranes, in particular the plasma membrane and the membrane of early endosomes. Several other Ca^2+-independent interaction partners of S100A10 have been described in the recent past. Many of these interactions, which have been shown to be of functional significance for the respective partner, involve plasma membrane-resident proteins. In most of these cases, S100A10, probably residing in a complex with annexin A2, appears to regulate the intracellular trafficking of the respective target protein and thus its functional expression at the cell surface. In this paper, we review the current information on S100A10 protein interactions placing a particular emphasis on data that contribute to an understanding of the mechanistic basis of the S100A10 action. Based on these data, we propose that S100A10 functions as a linker tethering certain transmembrane proteins to annexin A2 thereby assisting their traffic to the plasma membrane and/or their firm anchorage at certain membrane sites.
-
S100A10 p11 family friends and functions
Pflügers Archiv: European Journal of Physiology, 2007Co-Authors: Ursula Rescher, Volker GerkeAbstract:S100A10, also known as p11 or annexin 2 light chain, is a member of the S100 family of small, dimeric EF hand-type Ca2+-binding proteins that generally modulate cellular target proteins in response to intracellular Ca2+ signals. In contrast to all other S100 proteins, S100A10 is Ca2+ insensitive because of amino acid replacements in its Ca2+-binding loops that lock the protein in a permanently active state. Within cells, the majority of S100A10 resides in a tight heterotetrameric complex with the peripheral membrane-binding protein annexin A2 that directs the complex to specific target membranes, in particular the plasma membrane and the membrane of early endosomes. Several other Ca2+-independent interaction partners of S100A10 have been described in the recent past. Many of these interactions, which have been shown to be of functional significance for the respective partner, involve plasma membrane-resident proteins. In most of these cases, S100A10, probably residing in a complex with annexin A2, appears to regulate the intracellular trafficking of the respective target protein and thus its functional expression at the cell surface. In this paper, we review the current information on S100A10 protein interactions placing a particular emphasis on data that contribute to an understanding of the mechanistic basis of the S100A10 action. Based on these data, we propose that S100A10 functions as a linker tethering certain transmembrane proteins to annexin A2 thereby assisting their traffic to the plasma membrane and/or their firm anchorage at certain membrane sites.
-
functional expression of the epithelial ca2 channels trpv5 and trpv6 requires association of the S100A10 annexin 2 complex
The EMBO Journal, 2003Co-Authors: Stan F J Van De Graaf, Jean Prenen, Joost G J Hoenderop, Dimitra Gkika, Dennis Lamers, Olivier Staub, Bernd Nilius, Ursula Rescher, Volker Gerke, Rene J M BindelsAbstract:TRPV5 and TRPV6 constitute the Ca(2+) influx pathway in a variety of epithelial cells. Here, we identified S100A10 as the first auxiliary protein of these epithelial Ca(2+) channels using yeast two-hybrid and GST pull-down assays. This S100 protein forms a heterotetrameric complex with annexin 2 and associates specifically with the conserved sequence VATTV located in the C-terminal tail of TRPV5 and TRPV6. Of these five amino acids, the first threonine plays a crucial role since the corresponding mutants (TRPV5 T599A and TRPV6 T600A) exhibited a diminished capacity to bind S100A10, were redistributed to a subplasma membrane area and did not display channel activity. Using GST pull-down and co-immunoprecipitation assays we demonstrated that annexin 2 is part of the TRPV5-S100A10 complex. Furthermore, the S100A10-annexin 2 pair colocalizes with the Ca(2+) channels in TRPV5-expressing renal tubules and TRPV6-expressing duodenal cells. Importantly, downregulation of annexin 2 using annexin 2-specific small interfering RNA inhibited TRPV5 and TRPV6-mediated currents in transfected HEK293 cells. In conclusion, the S100A10-annexin 2 complex plays a crucial role in routing of TRPV5 and TRPV6 to plasma membrane.
-
Functional expression of the epithelial Ca2+ channels (TRPV5 and TRPV6) requires association of the S100A10–annexin 2 complex
The EMBO Journal, 2003Co-Authors: Stan F.j. Van De Graaf, Jean Prenen, Joost G J Hoenderop, Dimitra Gkika, Dennis Lamers, Olivier Staub, Bernd Nilius, Ursula Rescher, Volker Gerke, Rene J M BindelsAbstract:TRPV5 and TRPV6 constitute the Ca(2+) influx pathway in a variety of epithelial cells. Here, we identified S100A10 as the first auxiliary protein of these epithelial Ca(2+) channels using yeast two-hybrid and GST pull-down assays. This S100 protein forms a heterotetrameric complex with annexin 2 and associates specifically with the conserved sequence VATTV located in the C-terminal tail of TRPV5 and TRPV6. Of these five amino acids, the first threonine plays a crucial role since the corresponding mutants (TRPV5 T599A and TRPV6 T600A) exhibited a diminished capacity to bind S100A10, were redistributed to a subplasma membrane area and did not display channel activity. Using GST pull-down and co-immunoprecipitation assays we demonstrated that annexin 2 is part of the TRPV5-S100A10 complex. Furthermore, the S100A10-annexin 2 pair colocalizes with the Ca(2+) channels in TRPV5-expressing renal tubules and TRPV6-expressing duodenal cells. Importantly, downregulation of annexin 2 using annexin 2-specific small interfering RNA inhibited TRPV5 and TRPV6-mediated currents in transfected HEK293 cells. In conclusion, the S100A10-annexin 2 complex plays a crucial role in routing of TRPV5 and TRPV6 to plasma membrane.
-
The Annexin 2/S100A10 Complex Controls the Distribution of Transferrin Receptor-containing Recycling Endosomes
Molecular Biology of the Cell, 2003Co-Authors: Nicole Zobiack, Ursula Rescher, Carsten Ludwig, Dagmar Zeuschner, Volker GerkeAbstract:The Ca2+- and lipid-binding protein annexin 2, which resides in a tight heterotetrameric complex with the S100 protein S100A10 (p11), has been implicated in the structural organization and dynamics of endosomal membranes. To elucidate the function of annexin 2 and S100A10 in endosome organization and trafficking, we used RNA-mediated interference to specifically suppress annexin 2 and S100A10 expression. Down-regulation of both proteins perturbed the distribution of transferrin receptor- and rab11-positive recycling endosomes but did not affect uptake into sorting endosomes. The phenotype was highly specific and could be rescued by reexpression of the N-terminal annexin 2 domain or S100A10 in annexin 2- or S100A10-depleted cells, respectively. Whole-mount immunoelectron microscopy of the aberrantly localized recycling endosomes in annexin 2/S100A10 down-regulated cells revealed extensively bent tubules and an increased number of endosome-associated clathrin-positive buds. Despite these morphological alterations, the kinetics of transferrin uptake and recycling was not affected to a significant extent, indicating that the proper positioning of recycling endosomes is not a rate-limiting step in transferrin recycling. The phenotype generated by this transient loss-of-protein approach shows for the first time that the annexin 2/S100A10 complex functions in the intracellular positioning of recycling endosomes and that both subunits are required for this activity.
David M. Waisman - One of the best experts on this subject based on the ideXlab platform.
-
S100A10, a novel biomarker in pancreatic ductal adenocarcinoma.
Molecular Oncology, 2018Co-Authors: Moamen Bydoun, Andra M. Sterea, Henry Liptay, Andrea Uzans, Weei-yuarn Huang, Gloria J. Rodrigues, Ian C. G. Weaver, David M. WaismanAbstract:Pancreatic cancer is arguably the deadliest cancer type. The efficacy of current therapies is often hindered by the inability to predict patient outcome. As such, the development of tools for early detection and risk prediction is key for improving outcome and quality of life. Here, we introduce the plasminogen receptor S100A10 as a novel predictive biomarker and a driver of pancreatic tumor growth and invasion. We demonstrated that S100A10 mRNA and protein are overexpressed in human pancreatic tumors compared to normal ducts and nonductal stroma. S100A10 mRNA and methylation status were predictive of overall survival and recurrence-free survival across multiple patient cohorts. S100A10 expression was driven by promoter methylation and the oncogene KRAS. S100A10 knockdown reduced surface plasminogen activation, invasiveness, and in vivo growth of pancreatic cancer cell lines. These findings delineate the clinical and functional contribution of S100A10 as a biomarker in pancreatic cancer.
-
Mechanism of plasmin generation by S100A10
Thrombosis and Haemostasis, 2017Co-Authors: Victoria A Miller, Patricia A Madureira, Ain Adilliah Kamaludin, Jeffrey Komar, Vandna Sharma, Girish Sahni, Craig Thelwell, Colin Longstaff, David M. WaismanAbstract:Plasminogen (Pg) is cleaved to form plasmin by the action of specific plasminogen activators such as the tissue plasminogen activator (tPA). Although the interaction of tPA and Pg with the surface of the fibrin clot has been well characterised, their interaction with cell surface Pg receptors is poorly understood. S100A10 is a cell surface Pg receptor that plays a key role in cellular plasmin generation. In the present report, we have utilised domain-switched/deleted variants of tPA, truncated plasminogen variants and S100A10 site-directed mutant proteins to define the regions responsible for S100A10-dependent plasmin generation. In contrast to the established role of the finger domain of tPA in fibrin-stimulated plasmin generation, we show that the kringle-2 domain of tPA plays a key role in S100A10-dependent plasmin generation. The kringle-1 domain of plasminogen, indispensable for fibrin-binding, is also critical for S100A10-dependent plasmin generation. S100A10 retains activity after substitution or deletion of the carboxyl-terminal lysine suggesting that internal lysine residues contribute to its plasmin generating activity. These studies define a new paradigm for plasminogen activation by the plasminogen receptor, S100A10.
-
Cell surface protease activation during RAS transformation: Critical role of the plasminogen receptor, S100A10
Oncotarget, 2016Co-Authors: Patricia A Madureira, Paul A. O'connell, Moamen Bydoun, Alamelu G. Bharadwaj, Katy A. Garant, Patrick W.k. Lee, David M. WaismanAbstract:// Patricia A. Madureira 1 , Alamelu G. Bharadwaj 2 , Moamen Bydoun 3 , Katy Garant 3 , Paul O'Connell 2 , Patrick Lee 3 , David M. Waisman 2, 3 1 Centre for Biomedical Research (CBMR), University of Algarve, Campus of Gambelas, Faro, Portugal 2 Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada 3 Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada Correspondence to: David Waisman, email: david.waisman@dal.ca Keywords: S100A10, RAS, plasminogen, plasmin, annexin A2 Received: February 22, 2016 Accepted: June 12, 2016 Published: June 24, 2016 ABSTRACT The link between oncogenic RAS expression and the acquisition of the invasive phenotype has been attributed to alterations in cellular activities that control degradation of the extracellular matrix. Oncogenic RAS-mediated upregulation of matrix metalloproteinase 2 (MMP-2), MMP-9 and urokinase-type plasminogen activator (uPA) is critical for invasion through the basement membrane and extracellular matrix. The uPA converts cell surface-bound plasminogen to plasmin, a process that is regulated by the binding of plasminogen to specific receptors on the cell surface, however, the identity of the plasminogen receptors that function in this capacity is unclear. We have observed that transformation of cancer cells with oncogenic forms of RAS increases plasmin proteolytic activity by 2- to 4-fold concomitant with a 3-fold increase in cell invasion. Plasminogen receptor profiling revealed RAS-dependent increases in both S100A10 and cytokeratin 8. Oncogenic RAS expression increased S100A10 gene expression which resulted in an increase in S100A10 protein levels. Analysis with the RAS effector-loop mutants that interact specifically with Raf, Ral GDS pathways highlighted the importance of the RalGDS pathways in the regulation of S100A10 gene expression. Depletion of S100A10 from RAS-transformed cells resulted in a loss of both cellular plasmin generation and invasiveness. These results strongly suggest that increases in cell surface levels of S100A10, by oncogenic RAS, plays a critical role in RAS-stimulated plasmin generation, and subsequently, in the invasiveness of oncogenic RAS expressing cancer cells.
-
S100A10: A Key Regulator of Fibrinolysis
Fibrinolysis and Thrombolysis, 2014Co-Authors: Alexi P. Surette, David M. WaismanAbstract:Regulation of fibrinolytic activity can be achieved by several mechanisms, ranging from regulating the production and localization of the plasminogen activators and their inhibitors, the degradation and inactivation of plasmin via autoproteolysis, and the synthesis and localization of the cell surface receptors for plasminogen. Binding of the inactive zymogen plasminogen to its cell surface receptors has been shown to significantly increase the rate of its conversion to the active serine-protease plasmin by co-localizing plasminogen with its activators, the tissue-type plasminogen activator (tPA) and the urokinase-type plasminogen activator (uPA) [1–3].One such cell surface plasminogen receptor is S100A10 (p11) [4]. S100A10, a member of the S100 protein family, was initially discovered as an annexin A2 (p36) binding partner [5–7]. S100A10 has also been found to interact with other cellular proteins including the Rho GTPase-activating protein DLC1 [8], cytosolic phospholipase A2 [9], the serotonin 1B receptor [10] and various ion channels, including the potassium channel TASK-1 [11], the sodium channel Na(V)1.8 [12] and the calcium channels TRPV5 and TRPV6 [13]. However, the major binding partners of S100A10 on the cell surface are tPA and plasminogen [14]. The focus of this review will be to discuss the role that extracellular S100A10 plays in regulating the conversion of plasminogen to plasmin and the physiological consequences of that process (Figure 1).
-
On the contribution of S100A10 and annexin A2 to plasminogen activation and oncogenesis: an enduring ambiguity.
Future Oncology, 2014Co-Authors: Moamen Bydoun, David M. WaismanAbstract:Plasminogen receptors are becoming increasingly relevant in regulating many diseases such as cancer, stroke and inflammation. However, controversy has emerged concerning the putative role of some receptors, in particular annexin A2, in binding plasminogen. Several reports failed to account for the effects of annexin A2 on the stability and conformation of its binding partner S100A10. This has created an enduring ambiguity as to the actual function of annexin A2 in plasmin regulation. Supported by a long line of evidence, we conclude that S100A10, and not annexin A2, is the primary plasminogen receptor within the annexin A2-S100A10 complex and contributes to the plasmin-mediated effects that were originally ascribed to annexin A2.
Richard L Eckert - One of the best experts on this subject based on the ideXlab platform.
-
s100 proteins in the epidermis
Journal of Investigative Dermatology, 2004Co-Authors: Richard L Eckert, Annmarie Broome, Monica Ruse, Nancy A Robinson, David RyanAbstract:The S100 proteins comprise a family of 21 low molecular weight (9–13 kDa) proteins that are characterized by the presence of two calcium-binding EF-hand motifs. Fourteen S100 protein genes are located within the epidermal differentiation complex on human chromosome 1q21 and 13 S100 proteins (S100A2, S100A3, S100A4, S100A6, S100A7, S100A8, S100A9, S100A10, S100A11, S100A12, S100A15, S100B, and S100P) are expressed in normal and/or diseased epidermis. S100 proteins exist in cells as anti-parallel hetero- and homodimers and upon calcium binding interact with target proteins to regulate cell function. S100 proteins are of interest as mediators of calcium-associated signal transduction and undergo changes in subcellular distribution in response to extracellular stimuli. They also function as chemotactic agents and may play a role in the pathogenesis of epidermal disease, as selected S100 proteins are markedly overexpressed in psoriasis, wound healing, skin cancer, inflammation, cellular stress, and other epidermal states.
-
s100a7 S100A10 and s100a11 are transglutaminase substrates
Biochemistry, 2001Co-Authors: Monica Ruse, Nancy A Robinson, David Ryan, Adam Lambert, Kijoon Shon, Richard L EckertAbstract:S100 proteins are a family of 10−14 kDa EF-hand-containing calcium binding proteins that function to transmit calcium-dependent cell regulatory signals. S100 proteins have no intrinsic enzyme activity but bind in a calcium-dependent manner to target proteins to modulate target protein function. Transglutaminases are enzymes that catalyze the formation of covalent e-(γ-glutamyl)lysine bonds between protein-bound glutamine and lysine residues. In the present study we show that transglutaminase-dependent covalent modification is a property shared by several S100 proteins and that both type I and type II transglutaminases can modify S100 proteins. We further show that the reactive regions are at the solvent-exposed amino- and carboxyl-terminal ends of the protein, regions that specify S100 protein function. We suggest that transglutaminase-dependent modification is a general mechanism designed to regulate S100 protein function.
-
s100a11 S100A10 annexin i desmosomal proteins small proline rich proteins plasminogen activator inhibitor 2 and involucrin are components of the cornified envelope of cultured human epidermal keratinocytes
Journal of Biological Chemistry, 1997Co-Authors: Nancy A Robinson, Stephan Lapic, Jean F Welter, Richard L EckertAbstract:Abstract The cornified envelope (CE) is an insoluble sheath of e-(γ-glutamyl)lysine cross-linked protein, which is deposited beneath the plasma membrane during keratinocyte terminal differentiation. We have probed the structure of the CE by proteolytic cleavage of purified CE fragments isolated from CEs formed spontaneously in cell culture. CNBr digestion, followed by trypsin and then proteinase K treatment released 25%, 42%, and 18%, respectively, of the CE protein. Purification and sequencing of released peptides has identified two novel CE precursors, S100A11 (S100C, calgizzarin) and S100A10 (calpactin light chain). We also sequenced peptides derived from annexin I and plasminogen activator inhibitor 2, two putative envelope precursors, as well as portions of the well established CE precursor proteins SPR1A, SPR1B, and involucrin. Many desmosomal components were identified (desmoglein 3, desmocolin A/B, desmoplakin I, plakoglobin, and plakophilin), indicating that desmosomes become cross-linked into the CE. Fragments derived from envoplakin, the recently sequenced 210-kDa membranous CE precursor protein, which also appears to be a desmosomal component, were also identified. Analysis of the pattern of peptide release following the sequential digestion indicates that S100A11 is anchored to the envelope via Gln102 and/or Lys103at the carboxyl terminus and at Lys3, Lys23, and/or Gln22 in the amino terminus. A similar type of analysis indicates that small proline-rich proteins 1A and 1B (SPR1A and SPR1B) become cross-linked at the amino terminus (residues 1–23) and the carboxyl terminus (residues 86–89). No loricrin, cystatin A, or elafin peptides were detected.
David Ryan - One of the best experts on this subject based on the ideXlab platform.
-
s100 proteins in the epidermis
Journal of Investigative Dermatology, 2004Co-Authors: Richard L Eckert, Annmarie Broome, Monica Ruse, Nancy A Robinson, David RyanAbstract:The S100 proteins comprise a family of 21 low molecular weight (9–13 kDa) proteins that are characterized by the presence of two calcium-binding EF-hand motifs. Fourteen S100 protein genes are located within the epidermal differentiation complex on human chromosome 1q21 and 13 S100 proteins (S100A2, S100A3, S100A4, S100A6, S100A7, S100A8, S100A9, S100A10, S100A11, S100A12, S100A15, S100B, and S100P) are expressed in normal and/or diseased epidermis. S100 proteins exist in cells as anti-parallel hetero- and homodimers and upon calcium binding interact with target proteins to regulate cell function. S100 proteins are of interest as mediators of calcium-associated signal transduction and undergo changes in subcellular distribution in response to extracellular stimuli. They also function as chemotactic agents and may play a role in the pathogenesis of epidermal disease, as selected S100 proteins are markedly overexpressed in psoriasis, wound healing, skin cancer, inflammation, cellular stress, and other epidermal states.
-
s100a7 S100A10 and s100a11 are transglutaminase substrates
Biochemistry, 2001Co-Authors: Monica Ruse, Nancy A Robinson, David Ryan, Adam Lambert, Kijoon Shon, Richard L EckertAbstract:S100 proteins are a family of 10−14 kDa EF-hand-containing calcium binding proteins that function to transmit calcium-dependent cell regulatory signals. S100 proteins have no intrinsic enzyme activity but bind in a calcium-dependent manner to target proteins to modulate target protein function. Transglutaminases are enzymes that catalyze the formation of covalent e-(γ-glutamyl)lysine bonds between protein-bound glutamine and lysine residues. In the present study we show that transglutaminase-dependent covalent modification is a property shared by several S100 proteins and that both type I and type II transglutaminases can modify S100 proteins. We further show that the reactive regions are at the solvent-exposed amino- and carboxyl-terminal ends of the protein, regions that specify S100 protein function. We suggest that transglutaminase-dependent modification is a general mechanism designed to regulate S100 protein function.