ISSN:
1432-0983
Keywords:
G1 cyclins
;
N-glycosylation
;
Yeast
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract In budding yeast, one of three G1 cyclins is required for progression though START, when cells commit to a further round of cell division. We have identified mutations inALG1 (ERC14), a gene required for N-glycosylation, which are inviable in acln1 cln2 background but are rescued by over-expression ofCLNs.CLN1 andCLN2 are much more efficient thanCLN3 in rescuing theerc14-1 allele. Theerc14-1 allele results in a significant N-glycosylation defect, and no rescue of this defect byCLN1 over-expression was detected. These data suggest thatCLN over-expression could be allowing cells to live with lower levels of N-glycosylation, possibly by overcoming a checkpoint sensitive to N-glycosylation capacity. A plasmid suppressor ofalg1, PSA1, encodes a 361 amino-acid protein with homology to NDP-hexose pyrophosphorylases, the enzymes that catalyze the formation of activated sugar nucleotides.PSA1 is an essential gene, andPSA1 transcription is nearly co-ordinately regulated withCLN2 transcription, peaking near START. Co-ordinate regulation of glycosylation, sugar nucleotide metabolism, and cell-cycle progression through G1 may be a feature that ensures adequate cell-wall precursors are present before bud emergence.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02221573
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