The Experts below are selected from a list of 52008 Experts worldwide ranked by ideXlab platform
Naushad Ali - One of the best experts on this subject based on the ideXlab platform.
-
demonstration of Functional Requirement of polypyrimidine tract binding protein by selex rna during hepatitis c virus internal ribosome entry site mediated translation initiation
Journal of Biological Chemistry, 2000Co-Authors: Adil Anwar, Naushad Ali, Rasheeda Tanveer, Aleem SiddiquiAbstract:Abstract Polypyrimidine tract-binding protein (PTB) has been previously shown to physically interact with the hepatitis C virus (HCV) RNA genome at its 5′- and 3′-noncoding regions. Using high affinity SELEX RNA molecules, we present evidence for the Functional Requirement of PTB during HCV internal ribosome entry site (IRES)-controlled translation initiation. This study was carried out in rabbit reticulocyte translation lysates in which the HCV IRES-driven reporter RNA was introduced along with the PTB-specific SELEX RNA molecules. The SELEX RNAs specifically inhibited the HCV IRES function in the context of mono- and dicistronic mRNAs. The cap-dependent translation of a reporter (chloramphenicol acetyltransferase) RNA or naturally capped brome mosaic virus RNA, however, was not affected by the presence of SELEX during in vitro translation assays. The SELEX-mediated inhibition of the HCV IRES is shown to be relieved by the addition of recombinant human PTB in an add-back experiment. Thein vivo Requirement of PTB was further confirmed by cotransfection of Huh7 cells with reporter RNA and PTB-specific SELEX RNA. The HCV IRES activity was inhibited by the SELEX RNA in these cells, but not by an unrelated control RNA. Together, these results demonstrate the Functional Requirement of cellular PTB in HCV translation and further support the feasible use of SELEX RNA strategy in demonstrating the Functional relevance of cellular protein(s) in complex biological processes.
-
interaction of polypyrimidine tract binding protein with the 5 noncoding region of the hepatitis c virus rna genome and its Functional Requirement in internal initiation of translation
Journal of Virology, 1995Co-Authors: Naushad Ali, Andaleem SiddiquiAbstract:Initiation of translation of the human hepatitis C virus (HCV) RNA genome occurs by internal ribosome entry into the 5' noncoding region (5'NCR) in a cap-independent manner. The internal ribosome entry site of the HCV 5'NCR has been previously defined to encompass almost the entire 5'NCR. Here we report the interaction of polypyrimidine tract-binding protein (PTB) at three distinct regions within the 5'NCR by UV cross-linking assays. All three regions contain a consensus polypyrimidine tract motif. The evidence for the interaction of recombinant PTB at multiple sites within the 5'NCR is based on the use of 5'NCR mutants as competitors and by direct UV cross-linking of the mutant RNAs. Furthermore, the PTB isomers from HeLa nuclear extracts interact with the HCV 5'NCR, as shown by immunoprecipitation of a UV cross-linked complex with anti-PTB serum. Immunodepletion of PTB from translation lysates suggested the Functional Requirement for PTB during translation initiation of the HCV RNA. Addition of purified PTB to immunodepleted lysates did not restore translation mediated by the HCV 5'NCR, indicating the Requirement of PTB-associated factors that were removed during immunodepletion.
Aleem Siddiqui - One of the best experts on this subject based on the ideXlab platform.
-
demonstration of Functional Requirement of polypyrimidine tract binding protein by selex rna during hepatitis c virus internal ribosome entry site mediated translation initiation
Journal of Biological Chemistry, 2000Co-Authors: Adil Anwar, Naushad Ali, Rasheeda Tanveer, Aleem SiddiquiAbstract:Abstract Polypyrimidine tract-binding protein (PTB) has been previously shown to physically interact with the hepatitis C virus (HCV) RNA genome at its 5′- and 3′-noncoding regions. Using high affinity SELEX RNA molecules, we present evidence for the Functional Requirement of PTB during HCV internal ribosome entry site (IRES)-controlled translation initiation. This study was carried out in rabbit reticulocyte translation lysates in which the HCV IRES-driven reporter RNA was introduced along with the PTB-specific SELEX RNA molecules. The SELEX RNAs specifically inhibited the HCV IRES function in the context of mono- and dicistronic mRNAs. The cap-dependent translation of a reporter (chloramphenicol acetyltransferase) RNA or naturally capped brome mosaic virus RNA, however, was not affected by the presence of SELEX during in vitro translation assays. The SELEX-mediated inhibition of the HCV IRES is shown to be relieved by the addition of recombinant human PTB in an add-back experiment. Thein vivo Requirement of PTB was further confirmed by cotransfection of Huh7 cells with reporter RNA and PTB-specific SELEX RNA. The HCV IRES activity was inhibited by the SELEX RNA in these cells, but not by an unrelated control RNA. Together, these results demonstrate the Functional Requirement of cellular PTB in HCV translation and further support the feasible use of SELEX RNA strategy in demonstrating the Functional relevance of cellular protein(s) in complex biological processes.
Andaleem Siddiqui - One of the best experts on this subject based on the ideXlab platform.
-
interaction of polypyrimidine tract binding protein with the 5 noncoding region of the hepatitis c virus rna genome and its Functional Requirement in internal initiation of translation
Journal of Virology, 1995Co-Authors: Naushad Ali, Andaleem SiddiquiAbstract:Initiation of translation of the human hepatitis C virus (HCV) RNA genome occurs by internal ribosome entry into the 5' noncoding region (5'NCR) in a cap-independent manner. The internal ribosome entry site of the HCV 5'NCR has been previously defined to encompass almost the entire 5'NCR. Here we report the interaction of polypyrimidine tract-binding protein (PTB) at three distinct regions within the 5'NCR by UV cross-linking assays. All three regions contain a consensus polypyrimidine tract motif. The evidence for the interaction of recombinant PTB at multiple sites within the 5'NCR is based on the use of 5'NCR mutants as competitors and by direct UV cross-linking of the mutant RNAs. Furthermore, the PTB isomers from HeLa nuclear extracts interact with the HCV 5'NCR, as shown by immunoprecipitation of a UV cross-linked complex with anti-PTB serum. Immunodepletion of PTB from translation lysates suggested the Functional Requirement for PTB during translation initiation of the HCV RNA. Addition of purified PTB to immunodepleted lysates did not restore translation mediated by the HCV 5'NCR, indicating the Requirement of PTB-associated factors that were removed during immunodepletion.
Adil Anwar - One of the best experts on this subject based on the ideXlab platform.
-
demonstration of Functional Requirement of polypyrimidine tract binding protein by selex rna during hepatitis c virus internal ribosome entry site mediated translation initiation
Journal of Biological Chemistry, 2000Co-Authors: Adil Anwar, Naushad Ali, Rasheeda Tanveer, Aleem SiddiquiAbstract:Abstract Polypyrimidine tract-binding protein (PTB) has been previously shown to physically interact with the hepatitis C virus (HCV) RNA genome at its 5′- and 3′-noncoding regions. Using high affinity SELEX RNA molecules, we present evidence for the Functional Requirement of PTB during HCV internal ribosome entry site (IRES)-controlled translation initiation. This study was carried out in rabbit reticulocyte translation lysates in which the HCV IRES-driven reporter RNA was introduced along with the PTB-specific SELEX RNA molecules. The SELEX RNAs specifically inhibited the HCV IRES function in the context of mono- and dicistronic mRNAs. The cap-dependent translation of a reporter (chloramphenicol acetyltransferase) RNA or naturally capped brome mosaic virus RNA, however, was not affected by the presence of SELEX during in vitro translation assays. The SELEX-mediated inhibition of the HCV IRES is shown to be relieved by the addition of recombinant human PTB in an add-back experiment. Thein vivo Requirement of PTB was further confirmed by cotransfection of Huh7 cells with reporter RNA and PTB-specific SELEX RNA. The HCV IRES activity was inhibited by the SELEX RNA in these cells, but not by an unrelated control RNA. Together, these results demonstrate the Functional Requirement of cellular PTB in HCV translation and further support the feasible use of SELEX RNA strategy in demonstrating the Functional relevance of cellular protein(s) in complex biological processes.
Ed Manser - One of the best experts on this subject based on the ideXlab platform.
-
a Functional Requirement for pak1 binding to the kh 2 domain of the fragile x protein related fxr1
Molecular Cell, 2010Co-Authors: Zhuoshen Zhao, Yohendran Baskaran, Rong Li, Ed ManserAbstract:Summary Loss of fragile X mental retardation protein FMR1 is the most common genetic cause of mental deficiency in man. We find that both FMR1 and the related FXR1 serve as direct binding partners for the Cdc42 effector PAK1. This involves an 11 residue segment in the PAK1 autoinhibitory domain that is exposed upon kinase activation and binds the FXR1 KH2 domain. Active PAK1 can phosphorylate FXR1 at Ser420; antibodies to this site show increased phosphorylation when fragile X proteins are recruited to stress granules. During zebrafish muscle development, FXR1 Ser420 phosphorylation is needed for protein function. The familial FMR1(I304N) mutation is biologically inactive, and FXR1(I304N) fails to bind PAK1. A different PAK1 binding-deficient mutant, FXR1(Q348K/E352A), fails to rescue loss of Zf-FXR1 unless combined with a gain-of-function S420D phosphomimetic. This is the first documented protein partner for the KH(2) domain of FMR1 or FXR1, and it has several implications for signaling by fragile X proteins.
