Human meta-static lymph node (MLN) 64 is a late endosomal membrane protein, and carries this MENTAL (MLN64N-terminal) domain at its N-terminus. The domain is composed of four trans-membrane helices with three short intervening loops [1]. The function of the domain is to capture cholesterol and pass it to the associated START domain Pfam:PF01852 for transfer to a cytosolic acceptor protein or membrane. In mammals, the MENTAL domain is involved in the localisation of MLN64 and MENTHO in late endosomes, and also in homo-and of hetero-interactions of these two proteins [2].

1: MENTHO, a MLN64 homologue devoid of the START domain. Alpy F, Wendling C, Rio MC, Tomasetto C; J Biol Chem. 2002;277:50780-50787. PMID:12393907

2: Functional characterization of the MENTAL domain. Alpy F, Latchumanan VK, Kedinger V, Janoshazi A, Thiele C, Wendling C, Rio MC, Tomasetto C; J Biol Chem. 2005;280:17945-17952. PMID:15718238