High impact information on STS1

• STS1 also interacted with the second suppressor, RPN11, a subunit of the 26S proteasome, in the two-hybrid system [1].
• We found that Sts1p interacts directly with Srp1p in vitro and also in vivo, as judged by coimmunoprecipitation and two-hybrid analyses [1].
• DBF8 maps to chromosome IX near the centromere, and it encodes a 36-kDa protein that is essential for viability at all temperatures [2].
• Although they show no evidence of DNA damage, dbf8 mutants exhibit increased rates of chromosome loss and nondisjunction even at a permissive temperature [2].
• A chromosomal deletion of STS1 leads to viable delta sts1 cells of both mating types, suggesting that STS1 is not essential for cell growth [3].

Biological context of STS1

• Besides restoring partial temperature resistance to the sec23-11 mutant, overexpression of STS1 also overcomes both the RNA synthesis and the protein transport blocks in this mutant [4].
• Multicopy STS1 restores both protein transport and ribosomal RNA stability in a new yeast sec23 mutant allele [4].
• By screening for complementation of the hydroxyurea-sensitive phenotype we cloned the corresponding wild-type gene and found that it corresponds to the essential gene STS1 (also named DBF8) [5].
• Taken together, our data suggest that Dbf8p plays an essential role in chromosome segregation [2].
• DBF8 is an essential gene whose mutations result in delay in mitotic progression and chromosome instability [6].

Physical interactions of STS1

• The present data suggest that Sts1p may play a role in the transport of Rna15p from the cytoplasm to the nucleus [5].

Other interactions of STS1

• Evidence for separable functions of Srp1p, the yeast homolog of importin alpha (Karyopherin alpha): role for Srp1p and Sts1p in protein degradation [1].
• These features suggest that Sts1p may play a catalytic or regulatory role in conjunction with the more abundant Sec23p [4].
• Use of the two-hybrid system suggests that Sts1p does not interact directly with Rna15p, but may be active as a homodimer [5].

Analytical, diagnostic and therapeutic context of STS1

• Sts1p has an apparent molecular weight of 30 kDa and was confirmed to be a cytosolic protein by immunofluorescence analysis [5].

References