scholarly journals CAC3 (MSI1) Suppression ofRAS2G19V Is Independent of Chromatin Assembly Factor I and Mediated by NPR1

2001 ◽  
Vol 21 (5) ◽  
pp. 1784-1794 ◽  
Author(s):  
Stephen D. Johnston ◽  
Shinichiro Enomoto ◽  
Lisa Schneper ◽  
Mark C. McClellan ◽  
Florence Twu ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Signal Transduction Pathway ◽  
Degradation Pathway ◽  
Chromatin Assembly ◽  
Transduction Pathway ◽  
Factor I ◽  
Chromatin Assembly Factor ◽  
Camp Pathway ◽  
Independent Mechanism ◽  
Assembly Factor

ABSTRACT Cac3p/Msi1p, the Saccharomyces cerevisiae homolog of retinoblastoma-associated protein 48 (RbAp48), is a component of chromatin assembly factor I (CAF-I), a complex that assembles histones H3 and H4 onto replicated DNA. CAC3 overexpression also suppresses the RAS/cyclic AMP (cAMP) signal transduction pathway by an unknown mechanism. We investigated this mechanism and found that CAC3 suppression of RAS/cAMP signal transduction was independent of either CAC1 orCAC2, subunits required for CAF-I function.CAC3 suppression was also independent of other chromatin-modifying activities, indicating that Cac3p has at least two distinct, separable functions, one in chromatin assembly and one in regulating RAS function. Unlike Cac1p, which localizes primarily to the nucleus, Cac3p localizes to both the nucleus and the cytoplasm. In addition, Cac3p associates with Npr1p, a cytoplasmic kinase that stablizes several nutrient transporters by antagonizing a ubiquitin-mediated protein degradation pathway. Deletion ofNPR1, like overexpression of Cac3p, suppressed theRAS/cAMP pathway. Furthermore, NPR1overexpression interfered with the ability of CAC3 to suppress the RAS/cAMP pathway, indicating that extra Cac3p suppresses the RAS/cAMP pathway by sequestering Npr1p. Deletion of NPR1 did not affect the quantity, phosphorylation state, or localization of Ras2p. Consistent with the idea that Npr1p exerts its effect on the RAS/cAMP pathway by antagonizing a ubiquitin-mediated process, excess ubiquitin suppressed both the heat shock sensitivity and the sporulation defects caused by constitutive activation of the RAS/cAMP pathway. Thus, CAC3/MSI1 regulates the RAS/cAMP pathway via a chromatin-independent mechanism that involves the sequestration of Npr1p and may be due to the increased ubiquitination of an Npr1p substrate.

Assignment of the p60 Subunit of Chromatin Assembly Factor I to Chromosome 21q22.2

Genomics ◽  
1996 ◽  
Vol 34 (1) ◽  
pp. 148-150 ◽  
Author(s):  
D.K. Shea ◽  
M. Rutter ◽  
D. Lucente ◽  
M.K. McCormick
Keyword(s):  
Chromatin Assembly ◽  
Factor I ◽  
Chromatin Assembly Factor ◽  
Assembly Factor

scholarly journals Isolation of Degradation-Deficient Mutants Defective in the Targeting of Fructose-1,6-bisphosphatase into the Vacuole for Degradation in Saccharomyces cerevisiae

Genetics ◽  
1996 ◽  
Vol 143 (4) ◽  
pp. 1555-1566 ◽  
Author(s):  
Mark Hoffman ◽  
Hui-Ling Chiang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Signal Transduction ◽  
Carbon Source ◽  
Signal Transduction Pathway ◽  
Degradation Pathway ◽  
Transduction Pathway ◽  
Fructose 1,6 Bisphosphatase ◽  
Dependent Signal ◽  
Complementation Groups ◽  
Vacuolar Sorting

Abstract The key regulatory enzyme in the gluconeogenesis pathway, fructose-1,6-bisphosphatase (FBPase), is induced when Saccharomyces cerevisiae are grown in medium containing a poor carbon source. FBPase is targeted to the yeast vacuole for degradation when glucose-starved cells are replenished with fresh glucose. To identify genes involved in the FBPase degradation pathway, mutants that failed to degrade FBPase in response to glucose were isolated using a colony-blotting procedure. These vacuolar import and degradation-deficient (vid) mutants were placed into 20 complementation groups. They are distinct from the known sec, ups or pep mutants affecting protein secretion, vacuolar sorting and vacuolar proteolysis in that they sort CpY correctly and regulate osmotic pressure normally. Despite the presence of FBPase antigen in these mutants, FBPase is completely inactivated in all uid mutants, indicating that the c-AMP-dependent signal transduction pathway and inactivation must function properly in vid mutants. vid mutants block FBPase dzgradation by accumulating FBPase in the cytosol and also in small vesicles in the cytoplasm. FBPase may be targeted to small vesicles before uptake by the vacuole.

scholarly journals RLF2, a subunit of yeast chromatin assembly factor-I, is required for telomeric chromatin function in vivo.

1997 ◽  
Vol 11 (3) ◽  
pp. 358-370 ◽  
Author(s):  
S Enomoto ◽  
P D McCune-Zierath ◽  
M Gerami-Nejad ◽  
M A Sanders ◽  
J Berman
Keyword(s):  
Chromatin Assembly ◽  
Factor I ◽  
Chromatin Assembly Factor ◽  
Assembly Factor ◽  
A Subunit

scholarly journals Role of Saccharomyces cerevisiae Chromatin Assembly Factor-I in Repair of Ultraviolet Radiation Damage in Vivo

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 485-497 ◽  
Author(s):  
John C Game ◽  
Paul D Kaufman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Repair ◽  
Gene Silencing ◽  
Chromatin Assembly ◽  
Yeast Cells ◽  
Repair Gene ◽  
Uv Sensitivity ◽  
Factor I ◽  
Chromatin Assembly Factor ◽  
Assembly Factor

Abstract In vitro, the protein complex Chromatin Assembly Factor-I (CAF-I) from human or yeast cells deposits histones onto DNA templates after replication. In Saccharomyces cerevisiae, the CAC1, CAC2, and CAC3 genes encode the three CAF-I subunits. Deletion of any of the three CAC genes reduces telomeric gene silencing and confers an increase in sensitivity to killing by ultraviolet (UV) radiation. We used double and triple mutants involving cac1Δ and yeast repair gene mutations to show that deletion of the CAC1 gene increases the UV sensitivity of cells mutant in genes from each of the known DNA repair epistasis groups. For example, double mutants involving cac1Δ and excision repair gene deletions rad1Δ or rad14Δ showed increased UV sensitivity, as did double mutants involving cac1Δ and deletions of members of the RAD51 recombinational repair group. cac1Δ also increased the UV sensitivity of strains with defects in either the error-prone (rev3Δ) or error-free (pol30-46) branches of RAD6-mediated postreplicative DNA repair but did not substantially increase the sensitivity of strains carrying null mutations in the RAD6 or RAD18 genes. Deletion of CAC1 also increased the UV sensitivity and rate of UV-induced mutagenesis in rad5Δ mutants, as has been observed for mutants defective in error-free postreplicative repair. Together, these data suggest that CAF-I has a role in error-free postreplicative damage repair and may also have an auxiliary role in other repair mechanisms. Like the CAC genes, RAD6 is also required for gene silencing at telomeres. We find an increased loss of telomeric gene silencing in rad6Δ cac1Δ and rad18Δ cac1Δ double mutants, suggesting that CAF-I and multiple factors in the postreplicative repair pathway influence chromosome structure.

scholarly journals RRM3regulates epigenetic conversions inSaccharomyces cerevisiaein conjunction with Chromatin Assembly Factor I

Nucleus ◽  
2016 ◽  
Vol 7 (4) ◽  
pp. 405-414 ◽  
Author(s):  
Brandon Wyse ◽  
Roxanne Oshidari ◽  
Hollie Rowlands ◽  
Sanna Abbasi ◽  
Krassimir Yankulov
Keyword(s):  
Chromatin Assembly ◽  
Factor I ◽  
Chromatin Assembly Factor ◽  
Assembly Factor
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