This family represents CCDC47 proteins which are a component of the PAT complex, an endoplasmic reticulum (ER)-resident membrane multiprotein complex that facilitates multi-pass membrane proteins insertion into membranes [1]. The PAT complex, formed by CCDC47 and Asterix proteins, acts as an intramembrane chaperone by directly interacting with nascent transmembrane domains (TMDs), releasing its substrates upon correct folding, and is needed for optimal biogenesis of multi-pass membrane proteins [1]. CCDC47 (Swiss:Q96A33) is required to maintain the stability of Asterix [1,2]. CCDC47 is associated with various membrane-associated processes and is component of a ribosome-associated ER translocon complex involved in multi-pass membrane protein transport into the ER membrane and biogenesis [3]. It is also involved in the regulation of calcium ion homeostasis in the ER [4], being also required for proper protein degradation via the ERAD (ER-associated degradation) pathway [5].

1: An intramembrane chaperone complex facilitates membrane protein biogenesis. Chitwood PJ, Hegde RS; Nature. 2020;584:630-634. PMID:32814900

2: Different transmembrane domains associate with distinct endoplasmic reticulum components during membrane integration of a polytopic protein. Meacock SL, Lecomte FJ, Crawshaw SG, High S; Mol Biol Cell. 2002;13:4114-4129. PMID:12475939

3: An ER translocon for multi-pass membrane protein biogenesis. McGilvray PT, Anghel SA, Sundaram A, Zhong F, Trnka MJ, Fuller JR, Hu H, Burlingame AL, Keenan RJ; Elife. 2020; [Epub ahead of print] PMID:32820719

4: Bi-allelic CCDC47 Variants Cause a Disorder Characterized by Woolly Hair, Liver Dysfunction, Dysmorphic Features, and Global Developmental Delay. Morimoto M, Waller-Evans H, Ammous Z, Song X, Strauss KA, Pehlivan D, Gonzaga-Jauregui C, Puffenberger EG, Holst CR, Karaca E, Brigatti KW, Maguire E, Coban-Akdemir ZH, Amagata A, Lau CC, Chepa-Lotrea X, Macnamara E, Tos T, Isikay S, Nehrebecky M, Overton JD, Klein M, Markello TC, Posey JE, Adams DR, Lloyd-Evans E, Lupski JR, Gahl WA, Malicdan MCV; Am J Hum Genet. 2018;103:794-807. PMID:30401460

5: Contribution of calumin to embryogenesis through participation in the endoplasmic reticulum-associated degradation activity. Yamamoto S, Yamazaki T, Komazaki S, Yamashita T, Osaki M, Matsubayashi M, Kidoya H, Takakura N, Yamazaki D, Kakizawa S; Dev Biol. 2014;393:33-43. PMID:25009997