内膜系统运输

一.衔接蛋白

衔接蛋白有两类：AP1-5和GGA1-3.

AP复合体都是异四聚体，有五种，组成为（β）+（α/γ/δ/ε/ζ）+（μ）+（σ）

Adapter	Large Subunit	Localization	Sorting Motif	Coat Protein	Phospholipid	Small GTPase	Function
AP-1	γ1/2, β1, μ1A/B, σ1A/B/C	TGN/endosomes	YXXØ, [DE]XXXL[LI]	Clathrin	PI4P?	Arf-1	TGN↔endosomes, Polarized sorting
AP-2	αA/C, β2, μ2, σ2	Plasma membrane	YXXØ, [DE]XXXL[LI]	Clathrin	PIP2	Arf-6?	Clathrin-dependent endocytosis
AP-3	δ, β3A/B, μ3A/B, σ3A/B	Endosomes	YXXØ, [DE]XXXL[LI]	Clathrin?	Unknown	Arf-1	LRO biogenesis
AP-4	ε, β4, μ4, σ4	TGN	YX[FYL][FL]E	Unknown	Unknown	Arf-1	TGN→endosomes, Polarized sorting
AP-5	ζ, β5, μ5, σ5	Late endosomes	Unknown	SPG11/SPG15?	PI3P?	Unknown	Unknown