![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Vol. 12, Issue 7, 1957-1971, July 2001
Department of Cell Biology and Anatomy, The Johns Hopkins
University School of Medicine, Baltimore, Maryland 21205
Eukaryotic proteins that terminate in a CaaX motif undergo three
processing events: isoprenylation, C-terminal proteolytic cleavage, and
carboxyl methylation. In Saccharomyces cerevisiae, the
latter step is mediated by Ste14p, an integral endoplasmic reticulum membrane protein. Ste14p is the founding member of the isoprenylcysteine carboxyl methyltransferase (ICMT) family, whose members share significant sequence homology. Because the physiological substrates of Ste14p, such as Ras and the yeast a-factor precursor, are isoprenylated and reside on the cytosolic side of
membranes, the Ste14p residues involved in enzymatic activity are
predicted to be cytosolically disposed. In this study, we have
investigated the topology of Ste14p by analyzing the protease protection of epitope-tagged versions of Ste14p and the glycosylation status of Ste14p-Suc2p fusions. Our data lead to a topology model in
which Ste14p contains six membrane spans, two of which form a helical
hairpin. According to this model most of the Ste14p hydrophilic regions
are located in the cytosol. We have also generated ste14
mutants by random and site-directed mutagenesis to identify residues of
Ste14p that are important for activity. Notably, four of the five
loss-of-function mutations arising from random mutagenesis alter
residues that are highly conserved among the ICMT family. Finally, we
have identified a novel tripartite consensus motif in the C-terminal
region of Ste14p. This region is similar among all ICMT family members,
two phospholipid methyltransferases, several ergosterol biosynthetic
enzymes, and a group of bacterial open reading frames of unknown
function. Site-directed and random mutations demonstrate that residues
in this region play a critical role in the function of Ste14p.
This article has been cited by other articles:
|
|
 |
|
  Y. Tsegaye, C. G. Richardson, J. E. Bravo, B. J. Mulcahy, D. V. Lynch, J. E. Markham, J. G. Jaworski, M. Chen, E. B. Cahoon, and T. M. Dunn Arabidopsis Mutants Lacking Long Chain Base Phosphate Lyase Are Fumonisin-sensitive and Accumulate Trihydroxy-18:1 Long Chain Base Phosphate J. Biol. Chem., September 21, 2007; 282(38): 28195 - 28206. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Paul, K. Gable, and T. M. Dunn A Six-membrane-spanning Topology for Yeast and Arabidopsis Tsc13p, the Enoyl Reductases of the Microsomal Fatty Acid Elongating System J. Biol. Chem., June 29, 2007; 282(26): 19237 - 19246. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Huyer, A. Kistler, F. J. Nouvet, C. M. George, M. L. Boyle, and S. Michaelis Saccharomyces cerevisiae a-Factor Mutants Reveal Residues Critical for Processing, Activity, and Export. Eukaryot. Cell, September 1, 2006; 5(9): 1560 - 1570. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Kim, K. Melen, M. Osterberg, and G. von Heijne A global topology map of the Saccharomyces cerevisiae membrane proteome PNAS, July 25, 2006; 103(30): 11142 - 11147. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Miao, K. J. Ryan, and S. R. Wente The Integral Membrane Protein Pom34p Functionally Links Nucleoporin Subcomplexes Genetics, March 1, 2006; 172(3): 1441 - 1457. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. B. Hinckley, C. M. Reynolds, A. A. Ribeiro, S. C. McGrath, R. J. Cotter, F. N. Lauw, D. T. Golenbock, and C. R. H. Raetz A Leptospira interrogans Enzyme with Similarity to Yeast Ste14p That Methylates the 1-Phosphate Group of Lipid A J. Biol. Chem., August 26, 2005; 280(34): 30214 - 30224. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Anderson, B. S. Henriksen, R. A. Gibbs, and C. A. Hrycyna The Isoprenoid Substrate Specificity of Isoprenylcysteine Carboxylmethyltransferase: DEVELOPMENT OF NOVEL INHIBITORS J. Biol. Chem., August 19, 2005; 280(33): 29454 - 29461. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Imai, Y. Noda, H. Adachi, and K. Yoda A Novel Endoplasmic Reticulum Membrane Protein Rcr1 Regulates Chitin Deposition in the Cell Wall of Saccharomyces cerevisiae J. Biol. Chem., March 4, 2005; 280(9): 8275 - 8284. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Anderson, H. Frase, S. Michaelis, and C. A. Hrycyna Purification, Functional Reconstitution, and Characterization of the Saccharomyces cerevisiae Isoprenylcysteine Carboxylmethyltransferase Ste14p J. Biol. Chem., February 25, 2005; 280(8): 7336 - 7345. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Hofemeister and P. O'Hare Analysis of the Localization and Topology of Nurim, a Polytopic Protein Tightly Associated with the Inner Nuclear Membrane J. Biol. Chem., January 28, 2005; 280(4): 2512 - 2521. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. E. Linder and R. J. Deschenes Model organisms lead the way to protein palmitoyltransferases J. Cell Sci., February 15, 2004; 117(4): 521 - 526. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Shields, J. Y. Altarejos, X. Wang, L. B. Agellon, and D. E. Vance Molecular Dissection of the S-Adenosylmethionine-binding Site of Phosphatidylethanolamine N-Methyltransferase J. Biol. Chem., September 12, 2003; 278(37): 35826 - 35836. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Nilsson, A. E. Johnson, and G. von Heijne How Hydrophobic Is Alanine? J. Biol. Chem., August 8, 2003; 278(32): 29389 - 29393. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. E. Katz, M. Dlakic, and S. Clarke Automated Identification of Putative Methyltransferases from Genomic Open Reading Frames Mol. Cell. Proteomics, August 1, 2003; 2(8): 525 - 540. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Shields, R. Lehner, L. B. Agellon, and D. E. Vance Membrane Topography of Human Phosphatidylethanolamine N-Methyltransferase J. Biol. Chem., January 24, 2003; 278(5): 2956 - 2962. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Wittke, M. Dunnwald, M. Albertsen, and N. Johnsson Recognition of a Subset of Signal Sequences by Ssh1p, a Sec61p-related Protein in the Membrane of Endoplasmic Reticulum of Yeast Saccharomyces cerevisiae Mol. Biol. Cell, July 1, 2002; 13(7): 2223 - 2232. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Tam, W. K. Schmidt, and S. Michaelis The Multispanning Membrane Protein Ste24p Catalyzes CAAX Proteolysis and NH2-terminal Processing of the Yeast a-Factor Precursor J. Biol. Chem., December 7, 2001; 276(50): 46798 - 46806. [Abstract] [Full Text] [PDF]
|
|
