Clathrin adaptor proteins Clathrin adaptor proteins, also known as adaptins, are vesicular transport adaptor proteins associated with clathrin. These proteins are synthesized in the ribosomes, processed in the endoplasmic reticulum and transported from the Golgi apparatu ...

, also known as adaptins, are proteins that mediate the formation of

vesicles Vesicle may refer to: ; In cellular biology or chemistry * Vesicle (biology and chemistry), a supramolecular assembly of lipid molecules, like a cell membrane * Synaptic vesicle ; In human embryology * Vesicle (embryology), bulge-like features o ...

for intracellular trafficking and secretion. Adaptins are clustered subunits of adaptor protein (AP) complexes. There are several types of adaptin, each related to a different AP complex. Adaptins show

sequence similarity Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a sp ...

to some COPI subunits, thus they are thought to have a common evolutionary origin. The adaptin is a heterotetramer consisting of two large adaptins (beta and one other depending on the complex), a medium adaptin (mu), and a small adaptin (sigma): * complex 1 **

AP1B1 AP-1 complex subunit beta-1 is a protein that in humans is encoded by the ''AP1B1'' gene. Adaptor protein complex 1 is found at the cytoplasmic face of coated vesicles located at the Golgi complex, where it mediates both the recruitment of clathr ...

AP1G1 AP-1 complex subunit gamma-1 is a protein that in humans is encoded by the ''AP1G1'' gene. Function Adaptins are important components of clathrin-coated vesicles transporting ligand-receptor complexes from the plasma membrane or from the tran ...

** AP1G2 **

AP1M1 AP-1 complex subunit mu-1 is a protein that in humans is encoded by the ''AP1M1'' gene. Function The protein encoded by this gene is the medium chain of the trans-Golgi network clathrin-associated protein complex AP-1. The other components of ...

** AP1M2 **

AP1S1 AP-1 complex subunit sigma-1A is a protein that in humans is encoded by the ''AP1S1'' gene. Function The protein encoded by this gene is part of the clathrin coat assembly complex which links clathrin to receptors in coated vesicles. These ves ...

** AP1S2 *
AP1S3
* complex 2 ** AP2A1 ** AP2A2 **

AP2B1 AP-2 complex subunit beta is a protein that in humans is encoded by the ''AP2B1'' gene. Function The protein encoded by this gene is one of two large chain components of the AP2 adaptor complex, which serves to link clathrin to receptors in co ...

AP2M1 AP-2 complex subunit mu is a protein that in humans is encoded by the ''AP2M1'' gene. Function This gene encodes a subunit of the heterotetrameric coat assembly protein complex 2 (AP2), which belongs to the adaptor complexes medium subunits fa ...

AP2S1 AP-2 complex subunit sigma is a protein that in humans is encoded by the ''AP2S1'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' ...

* complex 3 **

AP3B1 AP-3 complex subunit beta-1 is a protein that in humans is encoded by the ''AP3B1'' gene. Function This gene encodes a protein that may play a role in organelle biogenesis associated with melanosomes, platelet dense granules, and lysosomes. Th ...

AP3B2 AP-3 complex subunit beta-2 is a protein that in humans is encoded by the ''AP3B2'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' ...

AP3D1 AP-3 complex subunit delta-1 is a protein that in humans is encoded by the ''AP3D1'' gene. Function AP3D1 is a subunit of the AP3 adaptor-like complex, which is not associated with clathrin. The AP3D1 subunit is implicated in intracellular bio ...

AP3M1 AP-3 complex subunit mu-1 is a protein that in humans is encoded by the ''AP3M1'' gene. The protein encoded by this gene is the medium subunit of AP-3, which is an adaptor-related protein complex associated with the Golgi region as well as more ...

*
AP3M2
**

AP3S1 AP-3 complex subunit sigma-1 is a protein that in humans is encoded by the ''AP3S1'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation' ...

AP3S2 AP-3 complex subunit sigma-2 is a protein that in humans is encoded by the ''AP3S2'' gene. Interactions AP3S2 has been shown to interact Advocates for Informed Choice, doing business as, dba interACT or interACT Advocates for Intersex Youth, ...

* complex 4 ** AP4B1 ** AP4E1 ** AP4M1 ** AP4S1 * complex 5 ** AP5Z1 ** AP5B1 ** AP5M1 ** AP5S1 A diagram of the 5 complexes is show
here

References

* Alberts, Johnson, Lewis, Raff, Roberts, Walter: ''Molecular Biology of the Cell'', 4th edition (2002), Garland Science. * Peripheral membrane proteins {{Membrane-protein-stub