| First Author | Phillips SE | Year | 2006 |
| Journal | Mol Biol Cell | Volume | 17 |
| Issue | 6 | Pages | 2498-512 |
| PubMed ID | 16540520 | Mgi Jnum | J:112524 |
| Mgi Id | MGI:3656448 | Doi | 10.1091/mbc.E06-01-0089 |
| Citation | Phillips SE, et al. (2006) Specific and nonspecific membrane-binding determinants cooperate in targeting phosphatidylinositol transfer protein beta-isoform to the mammalian trans-Golgi network. Mol Biol Cell 17(6):2498-512 |
| abstractText | Phosphatidylinositol transfer proteins (PITPs) regulate the interface between lipid metabolism and specific steps in membrane trafficking through the secretory pathway in eukaryotes. Herein, we describe the cis-acting information that controls PITPbeta localization in mammalian cells. We demonstrate PITPbeta localizes predominantly to the trans-Golgi network (TGN) and that this localization is independent of the phospholipid-bound state of PITPbeta. Domain mapping analyses show the targeting information within PITPbeta consists of three short C-terminal specificity elements and a nonspecific membrane-binding element defined by a small motif consisting of adjacent tryptophan residues (the W(202)W(203) motif). Combination of the specificity elements with the W(202)W(203) motif is necessary and sufficient to generate an efficient TGN-targeting module. Finally, we demonstrate that PITPbeta association with the TGN is tolerant to a range of missense mutations at residue serine 262, we describe the TGN localization of a novel PITPbeta isoform with a naturally occurring S262Q polymorphism, and we find no other genetic or pharmacological evidence to support the concept that PITPbeta localization to the TGN is obligately regulated by conventional protein kinase C (PKC) or the Golgi-localized PKC isoforms delta or epsilon. These latter findings are at odds with a previous report that conventional PKC-mediated phosphorylation of residue Ser262 is required for PITPbeta targeting to Golgi membranes. |
