SYBU and nervous system disorder: The TLC domain was named after three members of this large protein family (at least 70 homologs) that share sequence homology in their multi-pass transmembrane domain: TRAM (translocating chain-associated membrane protein, important for the translocation of transmembrane proteins during their synthesis in the rough ER), Lag1p (an ER-resident protein that facilitates ER to Golgi transport of glycosylphosphatidylinositol-anchored proteins) and CLN8 (a ubiquitously expressed ER and Golgi-localized protein that causes neurological disorders when mutated) (Winter and Ponting, 2002).