ARL1 and membrane traffic in Saccharomyces cerevisiae.
To examine the functions of the Arf-like protein, Arl1p, in Saccharomyces cerevisiae, a null allele, arl1delta::HIS3, was constructed in two strains. In one background only, loss of ARL1 resulted in temperature-sensitive (ts) growth (suppressed on high-osmolarity media). Allelic variation at the SSD1 locus accounted for differences between strains. Strains lacking ARL1 exhibited several defects in membrane traffic. First, arl1delta strains secreted less protein as measured by TCA-precipitable radioactivity found in the media of [(35)S]-labelled cells. A portion of newly synthesized carboxypeptidase Y (CPY) was secreted rather than correctly targeted to the vacuole. Uptake of the fluid-phase marker, lucifer yellow, was reduced. All these phenotypes were exacerbated in an ssd1 background. The ts phenotype of the arl1deltassd1 strain was suppressed by YPT1, the yeast Rab1a homologue, suggesting that ARL1 and YPT1 have partially overlapping functions. These findings demonstrate that ARL1 encodes a regulator of membrane traffic.
Rosenwald
Anne G
AG
Department of Biology, Georgetown University, Washington, DC 20057, USA. rosenwaa@georgetown.edu
Rhodes
Mary Ann
MA
Van Valkenburgh
Hillary
H
Palanivel
Vikram
V
Chapman
George
G
Boman
Annette
A
Zhang
Chun-jiang
CJ
Kahn
Richard A
RA
D020727:ADP-Ribosylation Factors; D000483:Alleles; D002268:Carboxypeptidases / Q000378:metabolism; D043402:Cathepsin A; D002462:Cell Membrane / Q000378:metabolism*; D004705:Endocytosis; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008854:Microscopy, Electron; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D002268:Carboxypeptidases; D043402:Cathepsin A; C097313:ADP-ribosylation factor related proteins; D020558:GTP Phosphohydrolases; D020727:ADP-Ribosylation Factors