Required for the post-translational delivery of tail-anchored (TA) proteins to the endoplasmic reticulum (PubMed:23041287). 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). Required for the stability of GET1 (By similarity). Stimulates calcium signaling in T cells through its involvement in elevation of intracellular calcium (By similarity). Essential for the survival of peripheral follicular B cells (By similarity). Component of the Golgi to ER traffic (GET) complex, which is composed of GET1/WRB, CAMLG/GET2 and GET3/TRC40 (PubMed:23041287). Within the complex, GET1 and CAMLG form a heterotetramer which is stabilized by phosphatidylinositol binding and which binds to the GET3 homodimer (By similarity). Interacts (via C-terminus) with GET1 (PubMed:23041287). Interacts (via N-terminus) with GET3 (PubMed:23041287). GET3 shows a higher affinity for CAMLG than for GET1 (By similarity). Interacts (via N-terminus) with TNFRSF13B/TACI (via C-terminus) (By similarity). In the central nervous system, expressed in astrocytes, microglia and neurons (at protein level).