Overexpression of MID2 suppresses the profilin-deficient phenotype of yeast cells.
Mol Microbiol
; 29(2): 515-26, 1998 Jul.
Article
en En
| MEDLINE
| ID: mdl-9720869
Profilin-deficient Saccharomyces cerevisiae cells show abnormal growth, actin localization, chitin deposition, bud formation and cytokinesis. Previous studies have also revealed a synthetic lethality between pfy1 and late secretory mutants, suggesting a role for profilin in intracellular transport. In this work, we document further the secretion defect associated with the pfy1delta mutant. Electron microscopic observations reveal an accumulation of glycoproteins in the bud and in the mother cell. The MATa, pfy1delta cells mate as well as wild-type cells, while the mating efficiency of MAT alpha, pfy1delta cells is reduced. Pulse-chase experiments demonstrate an accumulation of the 19 kDa alpha-factor precursor and delayed secretion of the mature alpha-factor. The TGN protein Kex2p is the principal enzyme responsible for the endoproteolytic cleavage of the alpha-factor precursor. An immunofluorescence detection of Kex2p shows an altered localization in pfy1delta cells. Instead of a discrete punctate distribution, the enzyme is dispersed throughout the cytoplasm. A high-copy-number plasmid containing MID2, which encodes a potential transmembrane protein involved in cell cycle control, suppresses the abnormal growth, actin distribution, alpha-factor maturation and the accumulation of intracellular membranous structures in pfy1delta cells.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Saccharomyces cerevisiae
/
Proteínas de Unión al Calcio
/
Proteínas de Ciclo Celular
/
Proteínas de Saccharomyces cerevisiae
/
Proproteína Convertasas
/
Proteínas de la Membrana
Idioma:
En
Revista:
Mol Microbiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Año:
1998
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Reino Unido