Molecular cloning of YPT1/SEC4-related cDNAs from an epithelial cell line.
Molecular analysis of Saccharomyces cerevisiae secretion mutants has led to the identification of two Ras-like GTP-binding proteins, Ypt1p and Sec4p, which are essential for transport along the exocytic route. To study the regulation of membrane traffic in epithelial cells, a set of 11 clones encoding proteins similar to the YPT1/SEC4 products were isolated from an MDCK (Madin-Darby canine kidney) cell cDNA library. Four of these proteins, Rab8, -9, -10, and -11, are novel members of this subfamily of Ras-like proteins, and two of them are closely related to Ypt1p and Sec4p. The ratio of the number of clones isolated over the total number screened reveals a high level of complexity for this subfamily of GTP-binding proteins. This diversity supports their proposed function in controlling different steps in membrane traffic.
Chavrier
P
P
European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
Vingron
M
M
Sander
C
C
Simons
K
K
Zerial
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002460:Cell Line; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D004848:Epithelium; D005656:Fungal Proteins / Q000235:genetics*; D019204:GTP-Binding Proteins / Q000235:genetics*; D015723:Gene Library; D008969:Molecular Sequence Data; D009154:Mutation; D011506:Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D020691:rab GTP-Binding Proteins
D004271:DNA, Fungal; D005656:Fungal Proteins; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D019204:GTP-Binding Proteins; C060755:YPT1 protein, S cerevisiae; C064320:SEC4 protein, S cerevisiae; D020691:rab GTP-Binding Proteins