ABCA3 transports PC, PG from ER membrane to lamellar body

ATP-binding cassette sub-family A member 3 (ABCA3) plays an important role in the formation of pulmonary surfactant, probably by transporting phospholipids such as phosphatidylcholine (PC) and phosphatidylglycerol (PG) from the ER membrane to lamellar bodies (LBs). PC and PG are the major phospholipid constituents of pulmonary surfactant. LBs are the surfactant storage organelles of type II epithelial cells from where phospholipids can be secreted together with surfactant proteins (SFTPs) into the alveolar airspace (Klugbauer & Hofmann 1996, Yamano et al. 2001). Defects in ABCA3 are the cause of pulmonary surfactant metabolism dysfunction type 3 (SMDP3; MIM:610921) (Shulenin et al. 2004).

ATP结合盒子亚家族A成员3（ABCA3）在肺表面活性物质的生成中扮演着至关重要的角色，其作用可能在于通过运输磷脂，如磷脂酰胆碱（PC）和磷脂酰甘油（PG），从内质网膜至亚层状体（LBs）。PC和PG是肺表面活性物质的主要磷脂成分。亚层状体是II型上皮细胞的表面活性物质储存器官，磷脂可在此与表面活性蛋白（SFTPs）一同分泌至肺泡气腔中（Klugbauer & Hofmann 1996，Yamano et al. 2001）。ABCA3的缺陷是导致肺表面活性物质代谢功能障碍3型（SMDP3；MIM:610921）的原因（Shulenin et al. 2004）。