Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The yeast chromosomal genes SKI2, SKI3, SKI4, SKI6, SKI7 and SKI8 repress the replication of double-stranded RNA viruses, protecting the host from the otherwise lethal effects of the virus. We cloned and sequenced the SKI3 gene and found that it encodes a 163 kDa protein including a typical nuclear localization signal. Cell fractionation experiments show that the SKI3 gene product is indeed tightly associated with nuclei and that the putative nuclear localization sequence directs beta-galactosidase into the nucleus. However, fusion of a part of the SKI3 protein lacking this signal with beta-galactosidase also directs beta-galactosidase into the nucleus, suggesting the presence of a second nuclear localization signal. The SKI3 gene is only essential in the presence of an M double-stranded RNA virus.
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PMID:Structure and nuclear localization signal of the SKI3 antiviral protein of Saccharomyces cerevisiae. 266 Apr 61

The SKI2 gene is part of a host system that represses the copy number of the L-A double-stranded RNA (dsRNA) virus and its satellites M and X dsRNA, of the L-BC dsRNA virus, and of the single-stranded replicon 20S RNA. We show that SKI2 encodes a 145-kDa protein with motifs characteristic of helicases and nucleolar proteins and is essential only in cells carrying M dsRNA. Unexpectedly, Ski2p does not repress M1 dsRNA copy number when M1 is supported by aN L-A cDNA clone; nonetheless, it did lower the levels of M1 dsRNA-encoded toxin produced. Since toxin secretion from cDNA clones of M1 is unaffected by Ski2p, these data suggest that Ski2p acts by specifically blocking translation of viral mRNAs, perhaps recognizing the absence of cap or poly(A). In support of this idea, we find that Ski2p represses production of beta-galactosidase from RNA polymerase I [no cap and no poly(A)] transcripts but not from RNA polymerase II (capped) transcripts.
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PMID:Evidence that the SKI antiviral system of Saccharomyces cerevisiae acts by blocking expression of viral mRNA. 832 Dec 35