Calcium signal-modulating cyclophilin ligand (CAML) was originally identified in a screen for cyclophilin B-interacting proteins. It is involved in calcium signalling [1] and in other signalling pathways as it interacts with many other signalling molecules including proto-oncogene tyrosine-protein kinase LCK, tumor necrosis factor receptor superfamily member 13B and EGFR [2-4]. It also mediates the membrane insertion of tail-anchored proteins (TA), acting as a TRC40 receptor (the homologue of yeast Get3) [5]. Although CAML shows no sequence similarity to yeast Get2, they share similar biochemical properties and topology [5], thus resulting in the Get2 homologue in mammals, playing the same essential role in the membrane insertion as that of Get2. It also shows similarity with ER membrane protein complex subunit 6 (EMC6) [5].

1: Calcium signalling in T cells stimulated by a cyclophilin B-binding protein. Bram RJ, Crabtree GR; Nature. 1994;371:355-358. PMID:7522304

2: CAML is a p56Lck-interacting protein that is required for thymocyte development. Tran DD, Edgar CE, Heckman KL, Sutor SL, Huntoon CJ, van Deursen J, McKean DL, Bram RJ; Immunity. 2005;23:139-152. PMID:16111633

3: NF-AT activation induced by a CAML-interacting member of the tumor necrosis factor receptor superfamily. von Bulow GU, Bram RJ; Science. 1997;278:138-141. PMID:9311921

4: CAML is required for efficient EGF receptor recycling. Tran DD, Russell HR, Sutor SL, van Deursen J, Bram RJ; Dev Cell. 2003;5:245-256. PMID:12919676

5: The emerging role of calcium-modulating cyclophilin ligand in posttranslational insertion of tail-anchored proteins into the endoplasmic reticulum membrane. Yamamoto Y, Sakisaka T; J Biochem. 2015;157:419-429. PMID:25869254

6: Structural basis for membrane insertion by the human ER membrane protein complex. Pleiner T, Tomaleri GP, Januszyk K, Inglis AJ, Hazu M, Voorhees RM; Science. 2020;369:433-436. PMID:32439656

7: Differential Modes of Orphan Subunit Recognition for the WRB/CAML Complex. Inglis AJ, Page KR, Guna A, Voorhees RM; Cell Rep. 2020;30:3691-3698. PMID:32187542