Interdomain interactions regulate the localization of a lipid transfer protein at ER-PM contact sites.
Title | Interdomain interactions regulate the localization of a lipid transfer protein at ER-PM contact sites. |
Publication Type | Journal Article |
Year of Publication | 2021 |
Authors | Basak B, Krishnan H, Padinjat R |
Journal | Biol Open |
Date Published | 2021 Feb 17 |
ISSN | 2046-6390 |
Abstract | During phospholipase C-β (PLC-β) signalling in photoreceptors, the phosphatidylinositol transfer protein (PITP) RDGB, is required for lipid transfer at endoplasmic reticulum (ER)-plasma membrane (PM) contact sites (MCS). Depletion of RDGB or its mis-localization away from the ER-PM MCS results in multiple defects in photoreceptor function. Previously, the interaction between the FFAT motif of RDGB and the integral ER protein dVAP-A was shown to be essential for accurate localization to ER-PM MCS. Here, we report that the FFAT/dVAP-A interaction alone is insufficient to localize RDGB accurately; this also requires the function of the C-terminal domains, DDHD and LNS2. Mutations in each of these domains results in mis-localization of RDGB leading to loss of function. While the LNS2 domain is necessary, it is not sufficient for the correct localization of RDGB, which also requires the C-terminal DDHD domain. The function of the DDHD domain is mediated through an intramolecular interaction with the LNS2 domain. Thus, interactions between the additional domains in a multi-domain PITP together lead to accurate localization at the MCS and signalling function. |
DOI | 10.1242/bio.057422 |
Alternate Journal | Biol Open |
PubMed ID | 33597200 |