Biochemical studies of Zmpste24-deficient mice.
Genetic studies in Saccharomyces cerevisiae identified two genes, STE24 and RCE1, involved in cleaving the three carboxyl-terminal amino acids from isoprenylated proteins that terminate with a CAAX sequence motif. Ste24p cleaves the carboxyl-terminal "-AAX" from the yeast mating pheromone a-factor, whereas Rce1p cleaves the -AAX from both a-factor and Ras2p. Ste24p also cleaves the amino terminus of a-factor. The mouse genome contains orthologues for both yeast RCE1 and STE24. We previously demonstrated, with a gene-knockout experiment, that mouse Rce1 is essential for development and that Rce1 is entirely responsible for the carboxyl-terminal proteolytic processing of the mouse Ras proteins. In this study, we cloned mouse Zmpste24, the orthologue for yeast STE24 and showed that it could promote a-factor production when expressed in yeast. Then, to assess the importance of Zmpste24 in development, we generated Zmpste24-deficient mice. Unlike the Rce1 knockout mice, Zmpste24-deficient mice survived development and were fertile. Since no natural substrates for mammalian Zmpste24 have been identified, yeast a-factor was used as a surrogate substrate to investigate the biochemical activities in membranes from the cells and tissues of Zmpste24-deficient mice. We demonstrate that Zmpste24-deficient mouse membranes, like Ste24p-deficient yeast membranes, have diminished CAAX proteolytic activity and lack the ability to cleave the amino terminus of the a-factor precursor. Thus, both enzymatic activities of yeast Ste24p are conserved in mouse Zmpste24, but these enzymatic activities are not essential for mouse development or for fertility.
Leung
G K
GK
Gladstone Institute of Cardiovascular Disease, University of California, San Francisco, California 94141-9100, USA.
Schmidt
W K
WK
Bergo
M O
MO
Gavino
B
B
Wong
D H
DH
Tam
A
A
Ashby
M N
MN
Michaelis
S
S
Young
S G
SG
D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D002678:Chimera; D003001:Cloning, Molecular; D017124:Conserved Sequence; D010450:Endopeptidases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D015723:Gene Library; D005822:Genetic Vectors; D006801:Humans; D008099:Liver / Q000378:metabolism; D000072235:Mating Factor; D008565:Membrane Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics; D010675:Pheromones / Q000235:genetics; D043484:Proprotein Convertases; D017368:Protein Prenylation; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D008565:Membrane Proteins; D010455:Peptides; D010675:Pheromones; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D000072235:Mating Factor; D010450:Endopeptidases; D043484:Proprotein Convertases; C491326:RCE1 protein, human; C491324:Rce1 protein, mouse; C105193:RCE1 protein, S cerevisiae; D008666:Metalloendopeptidases; C491251:STE24 protein, S cerevisiae; C491250:Zmpste24 protein, mouse