This is a family of unknown function. Family members are found in Bacteria and Eukaryotes. In algae, this family is found on the N-terminal of diphthamide synthase family Pfam:PF01902 and is predicted to be a membrane transporter belonging to The ATP-binding Cassette (ABC) family [1]. In nematoda, it is found on the N-terminal side of ribosomal protein family L14 Pfam:PF00238. It is also found on the N-terminal of Cob(I)alamin adenosyltransferase Pfam:PF01923 in other eukaryotes. Family members found in homo sapiens such as Swiss:Q5VUE5, have been shown to be highly expressed in 15 high-grade neuroendocrine tumor cell lines and YAP1-positive small-cell lung cancer cell lines [2] as well as being up-regulated in two human Multiple Myloma cell lines in response to selective nuclear export inhibitor KPT-276 [3]. The HMM profile of this family reveals 4 highly conserved cysteines.

1: Red and green algal origin of diatom membrane transporters: insights into environmental adaptation and cell evolution. Chan CX, Reyes-Prieto A, Bhattacharya D; PLoS One. 2011;6:e29138. PMID:22195008

2: Loss of YAP1 defines neuroendocrine differentiation of lung tumors. Ito T, Matsubara D, Tanaka I, Makiya K, Tanei ZI, Kumagai Y, Shiu SJ, Nakaoka HJ, Ishikawa S, Isagawa T, Morikawa T, Shinozaki-Ushiku A, Goto Y, Nakano T, Tsuchiya T, Tsubochi H, Komura D, Aburatani H, Dobashi Y, Nakajima J, Endo S, Fukayama M, Sekido Y, Niki T, Murakami Y; Cancer Sci. 2016;107:1527-1538. PMID:27418196

3: Genome-wide studies in multiple myeloma identify XPO1/CRM1 as a critical target validated using the selective nuclear export inhibitor KPT-276. Schmidt J, Braggio E, Kortuem KM, Egan JB, Zhu YX, Xin CS, Tiedemann RE, Palmer SE, Garbitt VM, McCauley D, Kauffman M, Shacham S, Chesi M, Bergsagel PL, Stewart AK; Leukemia. 2013;27:2357-2365. PMID:23752175