| Structural highlights
Function
[SMT3_YEAST] Not known; suppressor of MIF2 mutations. [CHP1_SCHPO] Component of the kinetochore which plays a role in stabilizing microtubules and so allowing accurate chromosome segregation. Has a role in the RNA interference (RNAi) pathway which is important for heterochromatin formation and accurate chromosome segregation. A member of the RNA-induced transcriptional silencing (RITS) complex which is involved in the biosynthesis of dsRNA from primer siRNAs provided by the RNA-directed RNA polymerase (RDRC) complex.[1] [2] [3] [4]
Publication Abstract from PubMed
RNA interference (RNAi) is critical for the assembly of heterochromatin at Schizosaccharomyces pombe centromeres. Central to this process is the RNA-induced initiation of transcriptional gene silencing (RITS) complex, which physically anchors small noncoding RNAs to chromatin. RITS includes Ago1, the chromodomain protein Chp1, and Tas3, which forms a bridge between Chp1 and Ago1. Chp1 is a large protein with no recognizable domains, apart from its chromodomain. Here we describe how the structured C-terminal half of Chp1 binds the Tas3 N-terminal domain, revealing the tight association of Chp1 and Tas3. The structure also shows a PIN domain at the C-terminal tip of Chp1 that controls subtelomeric transcripts through a post-transcriptional mechanism. We suggest that the Chp1-Tas3 complex provides a solid and versatile platform to recruit both RNAi-dependent and RNAi-independent gene-silencing pathways for locus-specific regulation of heterochromatin.
The Chp1-Tas3 core is a multifunctional platform critical for gene silencing by RITS.,Schalch T, Job G, Shanker S, Partridge JF, Joshua-Tor L Nat Struct Mol Biol. 2011 Nov 13;18(12):1351-7. doi: 10.1038/nsmb.2151. PMID:22081013[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Doe CL, Wang G, Chow C, Fricker MD, Singh PB, Mellor EJ. The fission yeast chromo domain encoding gene chp1(+) is required for chromosome segregation and shows a genetic interaction with alpha-tubulin. Nucleic Acids Res. 1998 Sep 15;26(18):4222-9. PMID:9722643
- ↑ Thon G, Verhein-Hansen J. Four chromo-domain proteins of Schizosaccharomyces pombe differentially repress transcription at various chromosomal locations. Genetics. 2000 Jun;155(2):551-68. PMID:10835380
- ↑ Motamedi MR, Verdel A, Colmenares SU, Gerber SA, Gygi SP, Moazed D. Two RNAi complexes, RITS and RDRC, physically interact and localize to noncoding centromeric RNAs. Cell. 2004 Dec 17;119(6):789-802. PMID:15607976 doi:10.1016/j.cell.2004.11.034
- ↑ Verdel A, Jia S, Gerber S, Sugiyama T, Gygi S, Grewal SI, Moazed D. RNAi-mediated targeting of heterochromatin by the RITS complex. Science. 2004 Jan 30;303(5658):672-6. Epub 2004 Jan 2. PMID:14704433 doi:10.1126/science.1093686
- ↑ Schalch T, Job G, Shanker S, Partridge JF, Joshua-Tor L. The Chp1-Tas3 core is a multifunctional platform critical for gene silencing by RITS. Nat Struct Mol Biol. 2011 Nov 13;18(12):1351-7. doi: 10.1038/nsmb.2151. PMID:22081013 doi:10.1038/nsmb.2151
|
