Lipid-binding START domain of mammalian STARD6 and related proteins
This subgroup includes the steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domains of mammalian STARD6 and related domains. It belongs to the START domain family, and in turn to the SRPBCC (START/RHO_alpha_C/PITP/Bet_v1/CoxG/CalC) domain superfamily of proteins that bind hydrophobic ligands. SRPBCC domains have a deep hydrophobic ligand-binding pocket. STARD6 is expressed in male germ cells of normal rats, and in the steroidogenic Leydig cells of perinatal hypothyroid testes. It may play a pivotal role in the steroidogenesis as well as in the spermatogenesis of normal rats. STARD6 has also been detected in the rat nervous system, and may participate in neurosteroid synthesis.