StAR Related Lipid Transfer Domain Containing Protein 10 (STARD10)

StarD10 contains a steroidogenic acute regulatory protein (StAR/StarD1)-related lipid transfer (START) domain that is thought to mediate binding of lipids. StarD10 interacts with phosphatidylcholine (PC) and phosphatidylethanolamine (PE) by electron spin resonance measurement. Binding was not restricted to lipid analogs since StarD10 selectively extracted PC and PE from small unilamellar vesicles prepared with endogenous radiolabeled lipids from Vero monkey kidney cells. Mass spectrometry revealed that StarD10 preferentially selects lipid species containing a palmitoyl or stearoyl chain on the sn-1 and an unsaturated fatty acyl chain on the sn-2 position. StarD10 was further shown to bind lipids in vivo by cross-linking of protein expressed in transfected HEK-293T cells with photoactivable phosphatidylcholine.