This is a family of proteins conserved from fungi to humans, including fungal Inclusion body clearance protein Iml2 protein, animal tetratricopeptide repeat protein 39A/B/C (TT39A/B/C) and some uncharacterised proteins. Members of this family carry a tetratricopeptide repeat Pfam:PF07719 at their C terminus. This entry includes Iml2 and its paralogue-YKR018C from S. cerevisiae; Iml2 localises to the cytoplasm and nucleus [1], and its expression is increased in response to DNA replication stress [2]. It is found to be involved in lipid droplet-mediated inclusion body clearing after protein folding stress [3]. In humans, TTC39A (also known as DEME6) is expressed in primary breast carcinomas but not in normal breast tissue, and has a putative eukaryotic RNP-1 RNA binding region and a candidate anchoring transmembrane domain. It is coordinately regulated with oestrogen receptor, but is not necessarily oestradiol-responsive [4]. TTC39B has been linked to lipid metabolism [5].

1: Global analysis of protein localization in budding yeast. Huh WK, Falvo JV, Gerke LC, Carroll AS, Howson RW, Weissman JS, O'Shea EK; Nature 2003;425:686-691. PMID:14562095

2: Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Tkach JM, Yimit A, Lee AY, Riffle M, Costanzo M, Jaschob D, Hendry JA, Ou J, Moffat J, Boone C, Davis TN, Nislow C, Brown GW; Nat Cell Biol. 2012;14:966-976. PMID:22842922

3: Lipid Droplets Are Essential for Efficient Clearance of Cytosolic Inclusion Bodies. Moldavski O, Amen T, Levin-Zaidman S, Eisenstein M, Rogachev I, Brandis A, Kaganovich D, Schuldiner M; Dev Cell. 2015;33:603-610. PMID:26004510

4: Differential screening and suppression subtractive hybridization identified genes differentially expressed in an estrogen receptor-positive breast carcinoma cell line. Kuang WW, Thompson DA, Hoch RV, Weigel RJ; Nucleic Acids Res. 1998;26:1116-1123. PMID:9461476

5: Genetic determinants of lipid traits in diverse populations from the population architecture using genomics and epidemiology (PAGE) study. Dumitrescu L, Carty CL, Taylor K, Schumacher FR, Hindorff LA, Ambite JL, Anderson G, Best LG, Brown-Gentry K, Buzkova P, Carlson CS, Cochran B, Cole SA, Devereux RB, Duggan D, Eaton CB, Fornage M, Franceschini N, Haessler J, Howard BV, Johnson KC, Laston S, Kolonel LN, Lee ET, MacCluer JW, Manolio TA, Pendergrass SA, Quibrera M, Shohet RV, Wilkens LR, Haiman CA, Le Marchand L, Buyske S, Kooperberg C, North KE, Crawford DC; PLoS Genet. 2011;7:e1002138. PMID:21738485