OSBPL5,8,10 exchange PS with PI4P from ER membrane to plasma membrane

Phosphatidylserine (PS) is a lipid component of cellular membranes. It is synthesised in the endoplasmic reticulum and then preferentially associates with the inner leaflet of the plasma membrane by as-yet unknown mechanisms. Intracellular lipids can travel through aqueous phases via transport vesicles or lipid-transfer proteins (LTPs). Oxysterol-binding protein-related proteins 5, 8 and 10 (OSBPL5, OSBPL8 and OSBPL10) bind and transport PS from ER compartments to the plasma membrane. They tether the ER to the plasma membrane via interaction of their pleckstrin homology domains with phosphatidylinositol 4-phosphate (PI4P) and mediate PI4P/PS countertransport between the ER and the plasma membrane (Du et al. 2011, Chung et al. 2015, Perttila et al. 2009, Maeda et al. 2013). OSBPL10 is also implicated in apolipoprotein B100 secretion (Nissila et al. 2012).

磷脂酰丝氨酸（PS）是细胞膜的一种脂质成分。其在内质网中合成，并通过尚未阐明的机制优先与质膜的内叶结合。细胞内的脂质可通过运输囊泡或脂质转移蛋白（LTPs）在水相中迁移。Oxysterol结合蛋白相关蛋白5、8和10（OSBPL5、OSBPL8和OSBPL10）与PS结合并将其从内质网区室运输至质膜。它们通过其pleckstrin同源结构域与磷脂酰肌醇4磷酸（PI4P）的相互作用将内质网锚定于质膜，并介导内质网与质膜之间的PI4P/PS逆向转运（Du等，2011；Chung等，2015；Perttila等，2009；Maeda等，2013）。OSBPL10还与载脂蛋白B100的分泌有关（Nissila等，2012）。