The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform

Kazutoshi Mori - One of the best experts on this subject based on the ideXlab platform.

  • endoplasmic reticulum stress induced mRNA splicing permits synthesis of transcription factor hac1p ern4p that activates the unfolded protein response
    Molecular Biology of the Cell, 1997
    Co-Authors: Tetsushi Kawahara, Hideki Yanagi, Takashi Yura, Kazutoshi Mori
    Abstract:

    An intracellular signaling from the endoplasmic reticulum (ER) to the nucleus, called the unfolded protein response (UPR), is activated when unfolded proteins are accumulated in the ER under a variety of stress conditions (“ER stress”). We and others recently identified Hac1p/Ern4p as a transcription factor responsible for the UPR in Saccharomyces cerevisiae. It was further reported that Hac1p (238 aa) is detected only in ER-stressed cells, and its expression is mediated by unconventional splicing of HAC1 Precursor mRNA. The splicing replaces the C-terminal portion of Hac1p; it was proposed that Precursor mRNA is also translated but the putative product of 230 aa is rapidly degraded by the ubiquitin–proteasome pathway. We have identified and characterized the same regulated splicing and confirmed its essential features. Contrary to the above proposal, however, we find that the 238-aa product of mature mRNA and the 230-aa-type protein tested are highly unstable with little or no difference in stability. Furthermore, we demonstrate that the absence of Hac1p in unstressed cells is due to the lack of translation of Precursor mRNA. We conclude that Hac1p is synthesized as the result of ER stress-induced mRNA splicing, leading to activation of the UPR.

  • Endoplasmic Reticulum Stress-induced mRNA Splicing Permits Synthesis of Transcription Factor Hac1p/Ern4p That Activates the Unfolded Protein Response
    Molecular biology of the cell, 1997
    Co-Authors: Tetsushi Kawahara, Hideki Yanagi, Takashi Yura, Kazutoshi Mori
    Abstract:

    An intracellular signaling from the endoplasmic reticulum (ER) to the nucleus, called the unfolded protein response (UPR), is activated when unfolded proteins are accumulated in the ER under a variety of stress conditions (“ER stress”). We and others recently identified Hac1p/Ern4p as a transcription factor responsible for the UPR in Saccharomyces cerevisiae. It was further reported that Hac1p (238 aa) is detected only in ER-stressed cells, and its expression is mediated by unconventional splicing of HAC1 Precursor mRNA. The splicing replaces the C-terminal portion of Hac1p; it was proposed that Precursor mRNA is also translated but the putative product of 230 aa is rapidly degraded by the ubiquitin–proteasome pathway. We have identified and characterized the same regulated splicing and confirmed its essential features. Contrary to the above proposal, however, we find that the 238-aa product of mature mRNA and the 230-aa-type protein tested are highly unstable with little or no difference in stability. Furthermore, we demonstrate that the absence of Hac1p in unstressed cells is due to the lack of translation of Precursor mRNA. We conclude that Hac1p is synthesized as the result of ER stress-induced mRNA splicing, leading to activation of the UPR.

Woanyuh Tarn - One of the best experts on this subject based on the ideXlab platform.

  • Functional interplay between viral and cellular SR proteins in control of post-transcriptional gene regulation
    The FEBS journal, 2008
    Co-Authors: Ming-chih Lai, Tsui-yi Peng, Woanyuh Tarn
    Abstract:

    Viruses take advantage of cellular machineries to facilitate their gene expression in the host. SR proteins, a superfamily of cellular Precursor mRNA splicing factors, contain a domain consisting of repetitive arginine/serine dipeptides, termed the RS domain. The authentic RS domain or variants can also be found in some virus-encoded proteins. Viral proteins may act through their own RS domain or through interaction with cellular SR proteins to facilitate viral gene expression. Numerous lines of evidence indicate that cellular SR proteins are important for regulation of viral RNA splicing and participate in other steps of post-transcriptional viral gene expression control. Moreover, viral infection may alter the expression levels or modify the phosphorylation status of cellular SR proteins and thus perturb cellular Precursor mRNA splicing. We review our current understanding of the interplay between virus and host in post-transcriptional regulation of gene expression via RS domain-containing proteins.

  • yeast Precursor mRNA processing protein prp19 associates with the spliceosome concomitant with or just after dissociation of u4 small nuclear rna
    Proceedings of the National Academy of Sciences of the United States of America, 1993
    Co-Authors: Woanyuh Tarn, Kuanrong Lee, Soochen Cheng
    Abstract:

    Abstract During assembly of the spliceosome, the U4 small nuclear RNA (snRNA) interacts with the spliceosome as a preformed U4/U6-U5 triple small nuclear ribonucleoprotein (snRNP) complex. Subsequently, U4 becomes loosely associated with the spliceosome, whereas U5 and U6 remain tightly associated, suggesting unwinding of the U4/U6 duplex. We show that this step of the assembly process can be blocked by limiting the ATP concentration in the splicing reaction. We also show that the yeast Precursor mRNA processing protein PRP19 becomes associated with the spliceosome during this transition. Thus, PRP19 may function in this step of spliceosome assembly.

Tetsushi Kawahara - One of the best experts on this subject based on the ideXlab platform.

  • endoplasmic reticulum stress induced mRNA splicing permits synthesis of transcription factor hac1p ern4p that activates the unfolded protein response
    Molecular Biology of the Cell, 1997
    Co-Authors: Tetsushi Kawahara, Hideki Yanagi, Takashi Yura, Kazutoshi Mori
    Abstract:

    An intracellular signaling from the endoplasmic reticulum (ER) to the nucleus, called the unfolded protein response (UPR), is activated when unfolded proteins are accumulated in the ER under a variety of stress conditions (“ER stress”). We and others recently identified Hac1p/Ern4p as a transcription factor responsible for the UPR in Saccharomyces cerevisiae. It was further reported that Hac1p (238 aa) is detected only in ER-stressed cells, and its expression is mediated by unconventional splicing of HAC1 Precursor mRNA. The splicing replaces the C-terminal portion of Hac1p; it was proposed that Precursor mRNA is also translated but the putative product of 230 aa is rapidly degraded by the ubiquitin–proteasome pathway. We have identified and characterized the same regulated splicing and confirmed its essential features. Contrary to the above proposal, however, we find that the 238-aa product of mature mRNA and the 230-aa-type protein tested are highly unstable with little or no difference in stability. Furthermore, we demonstrate that the absence of Hac1p in unstressed cells is due to the lack of translation of Precursor mRNA. We conclude that Hac1p is synthesized as the result of ER stress-induced mRNA splicing, leading to activation of the UPR.

  • Endoplasmic Reticulum Stress-induced mRNA Splicing Permits Synthesis of Transcription Factor Hac1p/Ern4p That Activates the Unfolded Protein Response
    Molecular biology of the cell, 1997
    Co-Authors: Tetsushi Kawahara, Hideki Yanagi, Takashi Yura, Kazutoshi Mori
    Abstract:

    An intracellular signaling from the endoplasmic reticulum (ER) to the nucleus, called the unfolded protein response (UPR), is activated when unfolded proteins are accumulated in the ER under a variety of stress conditions (“ER stress”). We and others recently identified Hac1p/Ern4p as a transcription factor responsible for the UPR in Saccharomyces cerevisiae. It was further reported that Hac1p (238 aa) is detected only in ER-stressed cells, and its expression is mediated by unconventional splicing of HAC1 Precursor mRNA. The splicing replaces the C-terminal portion of Hac1p; it was proposed that Precursor mRNA is also translated but the putative product of 230 aa is rapidly degraded by the ubiquitin–proteasome pathway. We have identified and characterized the same regulated splicing and confirmed its essential features. Contrary to the above proposal, however, we find that the 238-aa product of mature mRNA and the 230-aa-type protein tested are highly unstable with little or no difference in stability. Furthermore, we demonstrate that the absence of Hac1p in unstressed cells is due to the lack of translation of Precursor mRNA. We conclude that Hac1p is synthesized as the result of ER stress-induced mRNA splicing, leading to activation of the UPR.

Soochen Cheng - One of the best experts on this subject based on the ideXlab platform.

Takashi Yura - One of the best experts on this subject based on the ideXlab platform.

  • endoplasmic reticulum stress induced mRNA splicing permits synthesis of transcription factor hac1p ern4p that activates the unfolded protein response
    Molecular Biology of the Cell, 1997
    Co-Authors: Tetsushi Kawahara, Hideki Yanagi, Takashi Yura, Kazutoshi Mori
    Abstract:

    An intracellular signaling from the endoplasmic reticulum (ER) to the nucleus, called the unfolded protein response (UPR), is activated when unfolded proteins are accumulated in the ER under a variety of stress conditions (“ER stress”). We and others recently identified Hac1p/Ern4p as a transcription factor responsible for the UPR in Saccharomyces cerevisiae. It was further reported that Hac1p (238 aa) is detected only in ER-stressed cells, and its expression is mediated by unconventional splicing of HAC1 Precursor mRNA. The splicing replaces the C-terminal portion of Hac1p; it was proposed that Precursor mRNA is also translated but the putative product of 230 aa is rapidly degraded by the ubiquitin–proteasome pathway. We have identified and characterized the same regulated splicing and confirmed its essential features. Contrary to the above proposal, however, we find that the 238-aa product of mature mRNA and the 230-aa-type protein tested are highly unstable with little or no difference in stability. Furthermore, we demonstrate that the absence of Hac1p in unstressed cells is due to the lack of translation of Precursor mRNA. We conclude that Hac1p is synthesized as the result of ER stress-induced mRNA splicing, leading to activation of the UPR.

  • Endoplasmic Reticulum Stress-induced mRNA Splicing Permits Synthesis of Transcription Factor Hac1p/Ern4p That Activates the Unfolded Protein Response
    Molecular biology of the cell, 1997
    Co-Authors: Tetsushi Kawahara, Hideki Yanagi, Takashi Yura, Kazutoshi Mori
    Abstract:

    An intracellular signaling from the endoplasmic reticulum (ER) to the nucleus, called the unfolded protein response (UPR), is activated when unfolded proteins are accumulated in the ER under a variety of stress conditions (“ER stress”). We and others recently identified Hac1p/Ern4p as a transcription factor responsible for the UPR in Saccharomyces cerevisiae. It was further reported that Hac1p (238 aa) is detected only in ER-stressed cells, and its expression is mediated by unconventional splicing of HAC1 Precursor mRNA. The splicing replaces the C-terminal portion of Hac1p; it was proposed that Precursor mRNA is also translated but the putative product of 230 aa is rapidly degraded by the ubiquitin–proteasome pathway. We have identified and characterized the same regulated splicing and confirmed its essential features. Contrary to the above proposal, however, we find that the 238-aa product of mature mRNA and the 230-aa-type protein tested are highly unstable with little or no difference in stability. Furthermore, we demonstrate that the absence of Hac1p in unstressed cells is due to the lack of translation of Precursor mRNA. We conclude that Hac1p is synthesized as the result of ER stress-induced mRNA splicing, leading to activation of the UPR.