This family of transmembrane proteins includes the lipase maturation factor, LMF1. Lipoprotein lipase and hepatic lipase require LMF1 to fold into their active states [1]. It acts as a chaperone required for maturation and transport of active lipoprotein lipase (LPL), through the secretory pathway [2,3].

1: Mutations in LMF1 cause combined lipase deficiency and severe hypertriglyceridemia. Peterfy M, Ben-Zeev O, Mao HZ, Weissglas-Volkov D, Aouizerat BE, Pullinger CR, Frost PH, Kane JP, Malloy MJ, Reue K, Pajukanta P, Doolittle MH; Nat Genet. 2007;39:1483-1487. PMID:17994020

2: Mechanisms of lipase maturation. Doolittle MH, Peterfy M; Clin Lipidol. 2010;5:71-85. PMID:20543905

3: Purification, cellular levels, and functional domains of lipase maturation factor 1. Babilonia-Rosa MA, Neher SB; Biochem Biophys Res Commun. 2014;450:423-428. PMID:24909692