Gene Symbol: Ap2m1
Description: adaptor-related protein complex 2, mu 1 subunit
Alias: Ap50, Clapm1, mu2, AP-2 complex subunit mu, AP-2 mu chain, adapter-related protein complex 2 mu subunit, adapter-related protein complex 2 subunit mu, adaptor protein complex AP-2 subunit mu, adaptor-related protein complex 2 subunit mu, clathrin assembly protein complex 2 medium chain, clathrin assembly protein complex 2 mu medium chain, clathrin coat assembly protein AP50, clathrin coat-associated protein AP50, coat assembly protein complex 50 kD, mu2-adaptin, plasma membrane adaptor AP-2 50 kDa protein
Species: rat
Products:     Ap2m1

Top Publications

  1. Thurieau C, Brosius J, Burne C, Jolles P, Keen J, Mattaliano R, et al. Molecular cloning and complete amino acid sequence of AP50, an assembly protein associated with clathrin-coated vesicles. DNA. 1988;7:663-9 pubmed
    b>AP50 is the 50,000-dalton protein component found in clathrin-coated vesicles as part of the coat assembly protein (AP) complex, AP-2...
  2. Kelly B, Graham S, Liska N, Dannhauser P, Höning S, Ungewickell E, et al. Clathrin adaptors. AP2 controls clathrin polymerization with a membrane-activated switch. Science. 2014;345:459-63 pubmed publisher
    ..This molecular switching mechanism can couple AP2's membrane recruitment to its key functions of cargo and clathrin binding. ..
  3. Jackson L, Kelly B, McCoy A, Gaffry T, James L, Collins B, et al. A large-scale conformational change couples membrane recruitment to cargo binding in the AP2 clathrin adaptor complex. Cell. 2010;141:1220-9 pubmed publisher
    The AP2 adaptor complex (alpha, beta2, sigma2, and mu2 subunits) crosslinks the endocytic clathrin scaffold to PtdIns4,5P(2)-containing membranes and transmembrane protein cargo...
  4. Kim S, Ryan T. A distributed set of interactions controls mu2 functionality in the role of AP-2 as a sorting adaptor in synaptic vesicle endocytosis. J Biol Chem. 2009;284:32803-12 pubmed publisher
    ..Using quantitative endocytosis assays at nerve terminals, we examined how endocytosis depends on the integrity of mu2 function...
  5. Owen D, Evans P. A structural explanation for the recognition of tyrosine-based endocytotic signals. Science. 1998;282:1327-32 pubmed
    ..for endocytosis by a cytoplasmic sequence motif, tyrosine-X-X-(hydrophobic residue), that is recognized by the mu2 subunit of AP2 adaptors...
  6. Collins B, McCoy A, Kent H, Evans P, Owen D. Molecular architecture and functional model of the endocytic AP2 complex. Cell. 2002;109:523-35 pubmed
    ..We describe the structure of the 200 kDa AP2 "core" (alpha trunk, beta2 trunk, mu2, and sigma2) complexed with the polyphosphatidylinositol headgroup mimic inositolhexakisphosphate at 2...
  7. Wernick N, Haucke V, Simister N. Recognition of the tryptophan-based endocytosis signal in the neonatal Fc Receptor by the mu subunit of adaptor protein-2. J Biol Chem. 2005;280:7309-16 pubmed
    ..The best understood of these interactions occurs between the tyrosine-based motif, YXXPhi, and the mu2 subunit of AP-2...
  8. De Franceschi N, Arjonen A, Elkhatib N, Denessiouk K, Wrobel A, Wilson T, et al. Selective integrin endocytosis is driven by interactions between the integrin α-chain and AP2. Nat Struct Mol Biol. 2016;23:172-9 pubmed publisher
    ..We propose that integrins evolved to enable selective integrin-receptor turnover in response to changing matrix conditions. ..
  9. Keen J, Black M. The phosphorylation of coated membrane proteins in intact neurons. J Cell Biol. 1986;102:1325-33 pubmed
    ..A structural and functional counterpart to the 50-kD brain assembly polypeptide (AP50) was also identified in these neurons...

More Information


  1. Nakatsu F, Kadohira T, Gilbert D, Jenkins N, Kakuta H, Copeland N, et al. Genomic structure and chromosome mapping of the genes encoding clathrin-associated adaptor medium chains mu1A (Ap1m1) and mu1B (Ap1m2). Cytogenet Cell Genet. 1999;87:53-8 pubmed
    ..By contrast, these structures are different from that of the more distantly related Ap2m1 gene encoding mu2...
  2. Owen D, Setiadi H, Evans P, McEver R, Green S. A third specificity-determining site in mu 2 adaptin for sequences upstream of Yxx phi sorting motifs. Traffic. 2001;2:105-10 pubmed
    ..This structure suggests that some sequences can function as a 'three pinned plug', in which internalization activity is not critically dependent on any one of the three interacting side chains. ..
  3. Mishra S, Keyel P, Hawryluk M, Agostinelli N, Watkins S, Traub L. Disabled-2 exhibits the properties of a cargo-selective endocytic clathrin adaptor. EMBO J. 2002;21:4915-26 pubmed
  4. Saheki Y, De Camilli P. Synaptic vesicle endocytosis. Cold Spring Harb Perspect Biol. 2012;4:a005645 pubmed publisher
  5. Yu A, Xing Y, Harrison S, Kirchhausen T. Structural analysis of the interaction between Dishevelled2 and clathrin AP-2 adaptor, a critical step in noncanonical Wnt signaling. Structure. 2010;18:1311-20 pubmed publisher
    ..The crystal structure has thus allowed us to identify the specific interaction that leads to Frizzled uptake and to downstream, noncanonical signaling events. ..
  6. Kastning K, Kukhtina V, Kittler J, Chen G, Pechstein A, Enders S, et al. Molecular determinants for the interaction between AMPA receptors and the clathrin adaptor complex AP-2. Proc Natl Acad Sci U S A. 2007;104:2991-6 pubmed
    ..that an atypical basic motif within the cytoplasmic tails of AMPA-type glutamate receptors directly associates with mu2-adaptin by a mechanism similar to the recognition of the presynaptic vesicle protein synaptotagmin 1 by AP-2...
  7. Kim S, Ryan T. Synaptic vesicle recycling at CNS snapses without AP-2. J Neurosci. 2009;29:3865-74 pubmed publisher
    ..These results demonstrate that in the absence of AP-2, SV proteins still become endocytosed, and synaptic vesicle recycling remains operational. ..
  8. Boll W, Ohno H, Songyang Z, Rapoport I, Cantley L, Bonifacino J, et al. Sequence requirements for the recognition of tyrosine-based endocytic signals by clathrin AP-2 complexes. EMBO J. 1996;15:5789-95 pubmed
    ..We conclude that sorting into the endocytic pathway is governed by a surprisingly simple interaction between the mu 2 chain and a tyrosine-containing tetrapeptide sequence. ..
  9. Boll W, Rapoport I, Brunner C, Modis Y, Prehn S, Kirchhausen T. The mu2 subunit of the clathrin adaptor AP-2 binds to FDNPVY and YppØ sorting signals at distinct sites. Traffic. 2002;3:590-600 pubmed
    ..with a photoactivated peptide probe to demonstrate the interaction between FDNPVY-containing peptides and the mu2 chain of purified AP-2 clathrin adaptors (the complexes responsible for plasma membrane sorting)...
  10. Bai M, Gad H, Turacchio G, Cocucci E, Yang J, Li J, et al. ARFGAP1 promotes AP-2-dependent endocytosis. Nat Cell Biol. 2011;13:559-67 pubmed publisher
    ..The role of ARFGAP1 in AP-2-regulated endocytosis has mechanistic parallels with its roles in COPI transport, as both its GAP activity and coat function contribute to promoting AP-2 transport. ..
  11. Rapetti Mauss R, O Mahony F, Sepúlveda F, Urbach V, Harvey B. Oestrogen promotes KCNQ1 potassium channel endocytosis and postendocytic trafficking in colonic epithelium. J Physiol. 2013;591:2813-31 pubmed publisher
    ..This study has provided the first demonstration of hormonal regulation of KCNQ1 trafficking. In conclusion, we propose that internalization of KCNQ1 is a key event in the sustained antisecretory response to oestrogen. ..
  12. Stephens D, Crump C, Clarke A, Banting G. Serine 331 and tyrosine 333 are both involved in the interaction between the cytosolic domain of TGN38 and the mu2 subunit of the AP2 clathrin adaptor complex. J Biol Chem. 1997;272:14104-9 pubmed
    ..It was recently demonstrated that this motif specifically interacts with the mu2 subunit of the AP2 adaptor complex...
  13. Aguilar R, Ohno H, Roche K, Bonifacino J. Functional domain mapping of the clathrin-associated adaptor medium chains mu1 and mu2. J Biol Chem. 1997;272:27160-6 pubmed
    ..The medium chains of these complexes, mu1 and mu2, have been implicated in two types of interaction: assembly with the beta1 and beta2 chains of the corresponding ..
  14. Walther K, Diril M, Jung N, Haucke V. Functional dissection of the interactions of stonin 2 with the adaptor complex AP-2 and synaptotagmin. Proc Natl Acad Sci U S A. 2004;101:964-9 pubmed
    ..We hypothesize that stonin 2 may function as an AP-2-dependent sorting adaptor for synaptic vesicle recycling. ..
  15. Royle S, Bobanovic L, Murrell Lagnado R. Identification of a non-canonical tyrosine-based endocytic motif in an ionotropic receptor. J Biol Chem. 2002;277:35378-85 pubmed
    ..Mutation of either the tyrosine-binding pocket of the mu2 subunit of adaptor protein-2 or the YXXGL motif in the receptor C terminus caused a decrease in receptor ..
  16. Kittler J, Chen G, Honing S, Bogdanov Y, McAinsh K, Arancibia Carcamo I, et al. Phospho-dependent binding of the clathrin AP2 adaptor complex to GABAA receptors regulates the efficacy of inhibitory synaptic transmission. Proc Natl Acad Sci U S A. 2005;102:14871-6 pubmed
    ..Therefore phospho-dependent regulation of AP2 binding to GABA(A)Rs provides a mechanism to specify receptor cell surface number and the efficacy of inhibitory synaptic transmission. ..
  17. Royle S, Qureshi O, Bobanovic L, Evans P, Owen D, Murrell Lagnado R. Non-canonical YXXGPhi endocytic motifs: recognition by AP2 and preferential utilization in P2X4 receptors. J Cell Sci. 2005;118:3073-80 pubmed
    ..The crystal structure of a complex between residues 160-435 of the mu2 subunit of AP2 and a P2X4 C-terminal peptide showed that the YEQGL motif binds to mu2 at the same site as YXXPhi ..
  18. Dickson T, Mintz C, Benson D, Salton S. Functional binding interaction identified between the axonal CAM L1 and members of the ERM family. J Cell Biol. 2002;157:1105-12 pubmed
    ..Together, our data indicate that L1 binds directly to members of the ERM family and suggest this association may coordinate aspects of axonal morphogenesis. ..
  19. Miller S, Mathiasen S, Bright N, Pierre F, Kelly B, Kladt N, et al. CALM regulates clathrin-coated vesicle size and maturation by directly sensing and driving membrane curvature. Dev Cell. 2015;33:163-75 pubmed publisher
    ..CALM is thus a major factor in controlling CCV size and maturation and hence in determining the rates of endocytic cargo uptake. ..
  20. Tyukhtenko S, Deshmukh L, Kumar V, Lary J, Cole J, Lemmon V, et al. Characterization of the neuron-specific L1-CAM cytoplasmic tail: naturally disordered in solution it exercises different binding modes for different adaptor proteins. Biochemistry. 2008;47:4160-8 pubmed publisher
    ..In addition, we have shown that the juxtamembrane region of L1-CT has some binding affinity to AP2-mu2, although the specificity of this interaction needs further investigation...
  21. Kittler J, Chen G, Kukhtina V, Vahedi Faridi A, Gu Z, Tretter V, et al. Regulation of synaptic inhibition by phospho-dependent binding of the AP2 complex to a YECL motif in the GABAA receptor gamma2 subunit. Proc Natl Acad Sci U S A. 2008;105:3616-21 pubmed publisher
    ..These data define a mechanism for tyrosine kinase regulation of GABA(A)R surface levels and synaptic inhibition. ..
  22. Rapoport I, Miyazaki M, Boll W, Duckworth B, Cantley L, Shoelson S, et al. Regulatory interactions in the recognition of endocytic sorting signals by AP-2 complexes. EMBO J. 1997;16:2240-50 pubmed
    ..The mu2 subunit of isolated AP-2 complexes binds specifically, but rather weakly, to proteins bearing the tyrosine-based ..
  23. Hayashi H, Inamura K, Aida K, Naoi S, Horikawa R, Nagasaka H, et al. AP2 adaptor complex mediates bile salt export pump internalization and modulates its hepatocanalicular expression and transport function. Hepatology. 2012;55:1889-900 pubmed publisher
  24. Zhang Y, Moheban D, Conway B, Bhattacharyya A, Segal R. Cell surface Trk receptors mediate NGF-induced survival while internalized receptors regulate NGF-induced differentiation. J Neurosci. 2000;20:5671-8 pubmed
    ..Thus, interactions between Trk receptor tyrosine kinases and intracellular signaling molecules are dictated both by phosphotyrosine motifs within the receptors and by the intracellular location of phosphorylated receptors. ..