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). Component of the Golgi to ER traffic (GET) complex, which is composed of GET1/WRB, CAMLG/GET2 and GET3/TRC40 (PubMed:23041287, PubMed:24392163, PubMed:32910895). Within the complex, GET1 and CAMLG form a heterotetramer which is stabilized by phosphatidylinositol binding and which binds to the GET3 homodimer (PubMed:32910895). Interacts (via C-terminus) with GET1 (PubMed:24392163, PubMed:31417168, PubMed:32187542). Interacts (via N-terminus) with GET3 (By similarity). GET3 shows a higher affinity for CAMLG than for GET1 (PubMed:24392163). Interacts (via N-terminus) with TNFRSF13B/TACI (via C-terminus) (PubMed:9311921). (Microbial infection) Interacts with human herpes virus 8/HHV-8 protein K7; this interaction modulates intracellular calcium concentration. Ubiquitous. Highest levels in brain, testis and ovary.