Disease relevance of RTS1

• Expression of truncated forms of Rts1p can also partially suppress the ts phenotype and can fully suppress the inability of cells to grow on glycerol and the hypersensitivity of cells to ethanol [1].
• An epitope (influenza virus hemagglutinin)-tagged form of SCS1 in single copy complemented an SCS1-null allele [2].

High impact information on RTS1

• In the absence of Ipl1, Rts1 can initially bind to centromeric regions but disappears from these regions after anaphase I onset [3].
• Glucose effects on V-ATPase assembly did not involve the Ras-cyclic AMP pathway, Snf1p, protein kinase C, or the general stress response protein Rts1p [4].
• Strains in which RTS1 has been disrupted are temperature sensitive (ts) for growth, are hypersensitive to ethanol, are unable to grow with glycerol as their only carbon source, and accumulate at nonpermissive temperatures predominantly as large-budded cells with a 2N DNA content and a nondivided nucleus [1].
• The Saccharomyces cerevisiae gene RTS1 encodes a protein homologous to a variable B-type regulatory subunit of the mammalian heterotrimeric serine/threonine protein phosphatase 2A (PP2A) [1].
• However, CLB2 overexpression has no suppressive effects on other aspects of the rts1-null phenotype [1].

Biological context of RTS1

• Molecular genetic analysis of Rts1p, a B' regulatory subunit of Saccharomyces cerevisiae protein phosphatase 2A [1].
• This gene, SCS1 (suppressor of chaperonin sixty-1), encodes a 757-amino-acid protein of as yet unknown function which, nonetheless, has human, rice, and Caenorhabditis elegans homologs with high degrees (ca. 60%) of amino acid sequence identity [2].
• SCS1 is not an essential gene, but SCS1-null strains do not grow above 37 degrees C and show some growth-related defects at 30 degrees C as well [2].
• This cell cycle arrest can be overcome and partial suppression of the ts phenotype of rts1-null cells occurs if the gene CLB2, encoding a Cdc28 kinase-associated B-type cyclin, is expressed on a high-copy-number plasmid [1].
• We found the following: the level of each subunit remained constant throughout the cell cycle; there is at least 10 times more of one of the regulatory subunits (Rts1p) than the other (Cdc55p); Tpd3p, the structural subunit, is limiting for both catalytic and regulatory subunit binding [5].

Associations of RTS1 with chemical compounds

• Immunoprecipitated Rts1p was found associated with type 2A-specific protein phosphatase activity that is sensitive to 2 nM okadaic acid, but not to 100 nM phosphatase inhibitor-2, and to be phosphorylated in vivo [6].

Other interactions of RTS1

• A selection for high-copy suppressors of a ROX3 temperature-sensitive allele resulted in the isolation of RTS1, encoding a protein with homology to the B' regulatory subunit of protein phosphatase 2A0 [7].
• Deletion of RTS1 caused temperature and osmotic sensitivity and increased accumulation of CYC7 RNA under all conditions [7].
• E4orf4 required CDC55 to elicit its effect, whereas RTS1 was dispensable [8].
• Deletion of RTS1, encoding a regulatory subunit of protein phosphatase 2A, results in constitutive amino acid signaling via increased Stp1p processing [9].

References