当前位置： SCI文献检索 > MOLECULAR AND CELLULAR BIOLOGY期刊下所有文献 > GLC3 and GHA1 of Saccharomyces cerevisiae are allelic and encode the glycogen branching enzyme.

GLC3 and GHA1 of Saccharomyces cerevisiae are allelic and encode the glycogen branching enzyme.

Abstract：

:In the yeast Saccharomyces cerevisiae, glycogen serves as a major storage carbohydrate. In a previous study, mutants with altered glycogen metabolism were isolated on the basis of the altered iodine-staining properties of colonies. We found that when glycogen produced by strains carrying the glc-1p (previously called gha1-1) mutation is stained with iodine, the absorption spectrum resembles that of starch rather than that of glycogen, suggesting that this mutation might reduce the level of branching in the glycogen particles. Indeed, glycogen branching activity was undetectable in extracts from a glc3-1p strain but was elevated in strains which expressed GLC3 from a high-copy-number plasmid. These observations suggest that GLC3 encodes the glycogen branching enzyme. In contrast to glc3-1p, the glc3-4 mutation greatly reduces the ability of yeast to accumulate glycogen. These mutations appear to be allelic despite the striking difference in the phenotypes which they produce. The GLC3 clone complemented both glc3-1p and glc3-4. Deletions and transposon insertions in this clone had parallel effects on its ability to complement glc3-1p and glc3-4. Finally, a fragment of the cloned gene was able to direct the repair of both glc3-1p and glc3-4. Disruption of GLC3 yielded the glycogen-deficient phenotype, indicating that glycogen deficiency is the null phenotype. The glc3-1p allele appears to encode a partially functional product, since it is dominant over glc3-4 but recessive to GLC3. These observations suggest that the ability to introduce branches into glycogen greatly increases the ability of the cell to accumulate that polysaccharide. Northern (RNA) blot analysis identified a single mRNA of 2,300 nucleotides that increased in abundance ca. 20-fold as the culture approached stationary phase. It thus appears that the expression of GLC3 is regulated, probably at the level of transcription.

journal_name

Mol Cell Biol

journal_title

Molecular and cellular biology

authors

Rowen DW,Meinke M,LaPorte DC

doi

10.1128/mcb.12.1.22

subject

Has Abstract

pub_date

1992-01-01 00:00:00

pages

22-9

issue

eissn

0270-7306

issn

1098-5549

journal_volume

pub_type

杂志文章

在线工具

GLC3 and GHA1 of Saccharomyces cerevisiae are allelic and encode the glycogen branching enzyme.