| Title: | Biochemical studies of Zmpste24-deficient mice |
| Author(s): | Leung GK; Schmidt WK; Bergo MO; Gavino B; Wong DH; Tam A; Ashby MN; Michaelis S; Young SG; |
| Address: | "Gladstone Institute of Cardiovascular Disease, University of California, San Francisco, California 94141-9100, USA" |
| ISSN/ISBN: | 0021-9258 (Print) 0021-9258 (Linking) |
| Abstract: | "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" |
| Keywords: | "Amino Acid Sequence Animals Cell Membrane/physiology Chimera Cloning, Molecular Conserved Sequence Endopeptidases/deficiency/genetics/metabolism Gene Library Genetic Vectors Humans Liver/metabolism Mating Factor Membrane Proteins/deficiency/*genetics/*met;" |
| Notes: | "MedlineLeung, G K Schmidt, W K Bergo, M O Gavino, B Wong, D H Tam, A Ashby, M N Michaelis, S Young, S G eng AG15451/AG/NIA NIH HHS/ GM41223/GM/NIGMS NIH HHS/ HL41633/HL/NHLBI NIH HHS/ Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. 2001/06/16 J Biol Chem. 2001 Aug 3; 276(31):29051-8. doi: 10.1074/jbc.M102908200. Epub 2001 Jun 8" |
