ABC A-subclass proteins: Gatekeepers of cellular phospho- and sphingolipid transport

During the past years, available evidence suggests that members of a novel family of structurally highly related multispan proteins, designated ABC A-subclass transporters, exert critical functions in the control of cellular lipid transport processes. Loss-of-function scenarios, thus far, have revealed pivotal roles of individual ABC A-transporters in specialized lipid secretory pathways of the cell including HDL biogenesis (ABCA1), lung surfactant production (ABCA3), retinal integrity (ABCA4/ABCR) and skin lipid barrier formation (ABCA12). Although the specific transporter activities of many members of this novel protein family have not yet been established in detail, available evidence in…