Role of ELG1 in genome stability, telomere length regulation and telomeric silencing.
Shay Ben-Aroya, Sarit Smolikov, Yuval Mazor, Oren Parnas, Martin Kupiec
Mol. Micro & Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
The remarkable stability of the eukaryotic genome is achieved by the activity of many overlapping surveillance and repair mechanism. The yeast ELG1 gene plays a central role in keeping the genome stable. elg1 mutants exhibit increased rates of spontaneous recombination and gross chromosomal rearrangements during vegetative growth. In addition, they lose chromosomes at an enhanced rate, show hyper-transposition of natural repeated elements and exhibit elongated telomeres. Elg1 associates with the Rfc2-5 subunits of replication factor C (RFC) to form an RFC-like complex (RLC). Two additional RLCs have been previously discovered, in which Rad24 and Ctf18 take the place of Elg1. Genetic and biochemical data indicate that the Elg1, Ctf18 and Rad24 RLCs work in three separate pathways important for maintaining the integrity of the genome and for coping with various genomic stresses. The central role of ELG1 and its involvement in many aspects of the cell function is well demonstrated by genome -wide screens for mutants showing synthetic interactions with elg1. These include genes involved in homologous recombination, DNA replication, replication fork re-start, microtubule dynamics, checkpoints and histone maintenance/modification. We present results regarding the mechanisms by which elg1 mutants affect telomere length, telomeric silencing and genome-wide hyper-recombination.