Required for the post-translational delivery of tail-anchored (TA) proteins to the endoplasmic reticulum (PubMed:23041287, PubMed:24392163, PubMed:27226539). Together with GET1/WRB, acts as a membrane receptor for soluble GET3/TRC40, which recognizes and selectively binds the transmembrane domain of TA proteins in the cytosol (PubMed:23041287, PubMed:24392163, PubMed:27226539). Required for the stability of GET1 (PubMed:32187542). Stimulates calcium signaling in T cells through its involvement in elevation of intracellular calcium (PubMed:7522304). Essential for the survival of peripheral follicular B cells (By similarity).
