High impact information on SAC7

• SAC7 is a novel GTPase-activating protein for RHO1 [1].
• Deletion of SAC7, a gene originally identified as a suppressor of an actin mutation, also suppresses a tor2 mutation [1].
• Null alleles of SAC7 suppress temperature-sensitive actin mutations in Saccharomyces cerevisiae [2].
• One suppressor with a cold-sensitive growth phenotype defined the new gene, SAC7, which was mapped, cloned, sequenced, and disrupted [2].
• Disruption of the Rho1-GTPase-activating protein genes SAC7 and BEM2 leads to constitutive Slt2 activation, indicating their involvement as negative regulators of the pathway [3].

Other interactions of SAC7

• Here we show that BAG7, identified as the closest homologue of SAC7, also acts as a GAP for RHO1 in vitro and in vivo [4].
• Furthermore, we find that BAG7, SAC7, and BEM2 are functionally different in vivo [4].
• Pairwise combination of mutations in all these genes showed that the simultaneous deletion of SAC7 and LRG1 is synthetically lethal [5].
• We therefore suggest that Lrg1p acts as a negative regulator of the Pkc1p pathway in conjunction with its known homologue Sac7p [5].
• These results support the notion that the SAC7 gene product is involved in the normal assembly or function or both of actin [2].

References