Gic1 is a novel heterochromatin boundary protein in vivo

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Author(s)

Abstract

<p>In <i>Saccharomyces cerevisiae</i>, <i>HMR/HML</i>, telomeres and ribosomal DNA are heterochromatin-like regions in which gene transcription is prevented by the silent information regulator (Sir) complex. The Sir complex (Sir2, Sir3 and Sir4) can spread through chromatin from the silencer. Boundaries prevent Sir complex spreading, and we previously identified 55 boundary genes among all ~6,000 yeast genes. These boundary proteins can be distinguished into two types: those that activate transcription to prevent spreading of silencing, and those that prevent gene silencing by forming a boundary. We selected 44 transcription-independent boundary proteins from the 55 boundary genes by performing a one-hybrid assay and focused on <i>GIC1</i> (GTPase interaction component 1). Gic1 is an effector of Cdc42, which belongs to the Rho family of small GTPases, and has not been reported to function in heterochromatin boundaries in vivo. We detected a novel boundary-forming activity of Gic1 at <i>HMR</i>-left and telomeric regions by conducting a chromatin immunoprecipitation assay with an anti-Sir3 antibody. We also found that Gic1 bound weakly to histones in two-hybrid analysis. Moreover, we performed domain analysis to identify domain(s) of Gic1 that are important for its boundary activity, and identified two minimum domains, which are located outside its Cdc42-binding domain.</p>

Journal

  • Genes & Genetic Systems

    Genes & Genetic Systems 91(3), 151-159, 2016

    The Genetics Society of Japan

Codes

  • NII Article ID (NAID)
    130005170330
  • NII NACSIS-CAT ID (NCID)
    AA11077421
  • Text Lang
    ENG
  • ISSN
    1341-7568
  • NDL Article ID
    027722950
  • NDL Call No.
    Z53-W539
  • Data Source
    NDL  J-STAGE 
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