The Drosophila Su(var)2-10 locus regulates chromosome structure and function and encodes a member of the PIAS protein family.
The conserved heterochromatic location of centromeres in higher eukaryotes suggests that intrinsic properties of heterochromatin are important for chromosome inheritance. Based on this hypothesis, mutations in Drosophila melanogaster that alter heterochromatin-induced gene silencing were tested for effects on chromosome inheritance. Here we describe the characterization of the Su(var)2-10 locus, initially identified as a Suppressor of Position-Effect Variegation. Su(var)2-10 is required for viability, and mutations cause both minichromosome and endogenous chromosome inheritance defects. Mitotic chromosomes are improperly condensed in mutants, and polytene chromosomes are structurally abnormal and disorganized in the nucleus. Su(var)2-10 encodes a member of the PIAS protein family, a group of highly conserved proteins that control diverse functions. SU(VAR)2-10 proteins colocalize with nuclear lamin in interphase, and little to no SU(VAR)2-10 is found on condensed mitotic chromosomes. SU(VAR)2-10 is present at some polytene chromosome telomeres, and FISH analyses in mutant polytene nuclei revealed defects in telomere clustering and telomere-nuclear-lamina associations. We propose that Su(var2-10 controls multiple aspects of chromosome structure and function by establishing/maintaining chromosome organization in interphase nuclei.
Hari
K L
KL
Molecular and Cell Biology Laboratories, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
Cook
K R
KR
Karpen
G H
GH
D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D022004:Chromosome Structures / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D020868:Gene Silencing; D017404:In Situ Hybridization, Fluorescence; D051741:Kruppel-Like Transcription Factors; D008938:Mitosis / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D050828:Protein Inhibitors of Activated STAT; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D016615:Telomere / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases
D002352:Carrier Proteins; D002843:Chromatin; D004268:DNA-Binding Proteins; D051741:Kruppel-Like Transcription Factors; D009687:Nuclear Proteins; D050828:Protein Inhibitors of Activated STAT; D011506:Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C107961:ZBTB17 protein, human; C485521:Miz1 protein, mouse; D044767:Ubiquitin-Protein Ligases