4bj6

Structural highlights

Function

[RIF2_YEAST] Involved in transcriptional silencing and telomere length regulation. Its role in telomere length regulation results from either a block in elongation or promoting degradation of the telomere ends. Loss of RIF1 function results in derepression of an HMR silencer, whose ARS consensus element has been deleted, and in the elongation of telomeres. RAP1 may target the binding of RIF1 to silencers and telomeres. [RAP1_YEAST] Essential regulatory protein in yeast whose DNA-binding sites are found at three types of chromosomal elements: promoters, silencers, and telomeres. RAP1 is also involved in the regulation of telomere structure, where its binding sites are found within the terminal poly[C(1-3)A] sequences. The opposite regulatory functions of RAP1 are not intrinsic to its binding sites but, instead, result from interactions with different factors at promoters and silencers. RAP1 associates with SIR3 and SIR4 proteins to form a DNA-binding complex that initiates the repression at the HM loci and telomeres. May also target the binding of RIF1 and RIF2 to silencers and telomeres. Forms with GCR1 a transcriptional activation complex that is required for expression of glycolytic and ribosomal gene.

References

1. ↑ Shi T, Bunker RD, Mattarocci S, Ribeyre C, Faty M, Gut H, Scrima A, Rass U, Rubin SM, Shore D, Thoma NH. Rif1 and Rif2 Shape Telomere Function and Architecture through Multivalent Rap1 Interactions. Cell. 2013 Jun 6;153(6):1340-53. doi: 10.1016/j.cell.2013.05.007. PMID:23746845 doi:10.1016/j.cell.2013.05.007