ORP/Osh mediate cross-talk between ER-plasma membrane contact site components and plasma membrane SNAREs.

ORP/Osh mediate cross-talk between ER-plasma membrane contact site components and plasma membrane SNAREs.
Cell Mol Life Sci. 2020 Jul 30;:
Authors: Weber-Boyvat M, Trimbuch T, Shah S, Jäntti J, Olkkonen VM, Rosenmund C
Abstract
OSBP-homologous proteins (ORPs, Oshp) are lipid binding/transfer proteins. Several ORP/Oshp localize to membrane contacts between the endoplasmic reticulum (ER) and the plasma membrane, where they mediate lipid transfer or regulate lipid-modifying enzymes. A common way in which they target contacts is by binding to the ER proteins, VAP/Scs2p, while the second membrane is targeted by other interactions with lipids or proteins.We have studied the cross-talk of secretory SNARE proteins and their regulators with ORP/Oshp and VAPA/Scs2p at ER-plasma membrane contact sites in yeast and murine primary neurons. We show that Oshp-Scs2p interactions depend on intact secretory SNARE proteins, especially Sec9p. SNAP-25/Sec9p directly interact with ORP/Osh proteins and their disruption destabilized the ORP/Osh proteins, associated with dysfunction of VAPA/Scs2p. Deleting OSH1-3 in yeast or knocking down ORP2 in primary neurons reduced the oligomerization of VAPA/Scs2p and affected their multiple interactions with SNAREs. These observations reveal a novel cross-talk between the machineries of ER-plasma membrane contact sites and those driving exocytosis.
PMID: 32734583 [PubMed - as supplied by publisher]

Source: Cellular and Molecular Life Sciences : CMLS - July 29, 2020 Category: Cytology Authors: Weber-Boyvat M, Trimbuch T, Shah S, Jäntti J, Olkkonen VM, Rosenmund C Tags: Cell Mol Life Sci Source Type: research