A non-chromosomal factor allows viability of Schizosaccharomyces pombe lacking the essential chaperone calnexin.
J Cell Sci
; 117(Pt 6): 907-18, 2004 Feb 29.
Article
em En
| MEDLINE
| ID: mdl-14963023
ABSTRACT
Calnexin is a molecular chaperone playing key roles in protein folding and the quality control of this process in the endoplasmic reticulum. We, and others, have previously demonstrated that cnx1(+), the gene encoding the calnexin homologue in Schizosaccharomyces pombe, is essential for viability. We show that a particular cnx1 mutant induces a novel mechanism allowing the survival of S. pombe cells in the absence of calnexin/Cnx1p. Calnexin independence is dominant in diploid cells and is inherited in a non-Mendelian manner. Remarkably, this survival pathway, bypassing the necessity for calnexin, can be transmitted by transformation of cell extracts into a wild-type naive strain, thus implicating a non-chromosomal factor. Nuclease and UV treatments of cells extracts did not obliterate transmission of calnexin independence by transformation. However, protease digestion of extracts did reduce the appearance of calnexin-independent cells, indicating that a protein element is required for calnexin-less viability. We discuss a model in which this calnexin-less survival mechanism would be activated and perpetuated by a protein component acting as a genetic element.
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Bases de dados:
MEDLINE
Assunto principal:
Schizosaccharomyces
/
Calnexina
/
Retículo Endoplasmático
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Cell Sci
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Canadá