SEC65 gene product is a subunit of the yeast signal recognition particle required for its integrity

• Published in: Nature (London) Vol. 356; no. 6369; pp. 532 - 533
• Main Authors: Hann, B.C, Stirling, C.J, Walter, P
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 09.04.1992; Nature Publishing Group
• Subjects: Biological and medical sciences; Biological Transport, Active - genetics; Blotting, Western; Cell Division - genetics; Cellular biology; DNA; Fundamental and applied biological sciences. Psychology; Fungal Proteins - chemistry; Fungal Proteins - isolation & purification; Fungal Proteins - metabolism; genes; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Microbiology; mutants; Mycology; Proteins - pharmacokinetics; Ribonucleoproteins - chemistry; Ribonucleoproteins - isolation & purification; Ribonucleoproteins - physiology; RNA; Saccharomyces cerevisiae; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins; SEC65 protein; Signal Recognition Particle; Fungi; Proteins; Yeast; Stability; Molecular association; Ascomycetes; Molecular targeting; Saccharomyces cerevisiae; Thallophyta
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/356532a0

Protein targeting to the endoplasmic reticulum (ER) in mammalian cells is catalysed by the signal recognition particle (SRP), which consists of six protein subunits and an RNA subunit. Saccharomyces cerevisiae SRP is a 16S particle, of which only two subunits have been identified: a protein subunit, SRP54p, which is homologous to the mammalian SRP54 subunit, and an RNA subunit, scR1 (ref. 3). The sec65-1 mutant yeast cells are temperature-sensitive for growth and defective in the translocation of several secreted and membrane-bound proteins. The DNA sequence of the SEC65 gent suggests that its product is related to mammalian SRP19 subunit and may have a similar function. Here we show that SEC65p is a subunit of the S. cerevisiae SRP and that it is required for the stable association of another subunit, SRP54p, with SRP. Overexpression of SRP54p suppresses both growth and protein translocation defects in sec65-1 mutant cells.