Prenylation-dependent association of protein-tyrosine phosphatases PRL-1, -2, and -3 with the plasma membrane and the early endosome.
PRL-1, -2, and -3 represent a novel class of protein-tyrosine phosphatase with a C-terminal prenylation motif. Although PRL-1 has been suggested to be associated with the nucleus, the presence of three highly homologous members and the existence of a prenylation motif call for a more detailed examination of their subcellular localization. In the present study, we first demonstrate that mouse PRL-1, -2, and -3 are indeed prenylated. Examination of N-terminal epitope-tagged PRL-1, -2, and -3 expressed in transiently transfected cells suggests that PRL-1, -2, and -3 are present on the plasma membrane and intracellular punctate structures. Stable Chinese hamster ovary cells expressing PRL-1 and -3 in an inducible manner were established. When cells were treated with brefeldin A, PRL-1 and -3 accumulated in a collapsed compact structure around the microtubule-organizing center. Furthermore, PRL-1 and -3 redistributed into swollen vacuole-like structures when cells were treated with wortmannin. These characteristics of PRL-1 and -3 are typical for endosomal proteins. Electron microscope immunogold labeling reveals that PRL-1 and -3 are indeed associated with the plasma membrane and the early endosomal compartment. Expression of PRL-3 is detected in the epithelial cells of the small intestine, where PRL-3 is present in punctate structures in the cytoplasm. When cells are treated with FTI-277, a selective farnesyltransferase inhibitor, PRL-1, -2, and -3 shifted into the nucleus. Furthermore, a mutant form of PRL-2 lacking the C-terminal prenylation signal is associated with the nucleus. These results establish that the primary association of PRL-1, -2, and -3 with the membrane of the cell surface and the early endosome is dependent on their prenylation and that nuclear localization of these proteins may be triggered by a regulatory event that inhibits their prenylation.
Zeng
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Institute of Molecular and Cell Biology, 30 Medical Drive, Singapore 117609, Republic of Singapore.
Si
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Horstmann
H
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Xu
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Hong
W
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Pallen
C J
CJ
D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors; D000818:Animals; D020126:Brefeldin A / Q000494:pharmacology; D016466:CHO Cells; D002462:Cell Membrane / Q000201:enzymology* / Q000648:ultrastructure; D006224:Cricetinae; D011992:Endosomes / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051231:Farnesyltranstransferase; D017874:Immediate-Early Proteins / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000166:cytology / Q000201:enzymology; D008715:Methionine / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D008871:Microvilli / Q000201:enzymology / Q000648:ultrastructure; D017368:Protein Prenylation; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection
D004791:Enzyme Inhibitors; C096856:FTI 277; D017874:Immediate-Early Proteins; C111534:Ptp4a3 protein, mouse; D011994:Recombinant Proteins; D020126:Brefeldin A; D008715:Methionine; D019883:Alkyl and Aryl Transferases; D051231:Farnesyltranstransferase; D017027:Protein Tyrosine Phosphatases; C087359:Ptp4a1 protein, mouse; C111533:Ptp4a2 protein, mouse