Gene Symbol: AP1M2
Description: adaptor related protein complex 1 subunit mu 2
Alias: AP1-mu2, HSMU1B, MU-1B, MU1B, mu2, AP-1 complex subunit mu-2, AP-mu chain family member mu1B, HA1 47 kDa subunit 2, adaptor protein complex AP-1 mu-2 subunit, adaptor related protein complex 1 mu 2 subunit, clathrin assembly protein complex 1 mu-2 medium chain 2, clathrin coat assembly protein AP47 2, clathrin coat associated protein AP47 2, clathrin-associated adaptor medium chain mu2, golgi adaptor AP-1 47 kDa protein, golgi adaptor HA1/AP1 adaptin mu-2 subunit, mu-adaptin 2, mu1B-adaptin
Species: human
Products:     AP1M2

Top Publications

  1. 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...
  2. Hirst J, Robinson M. Clathrin and adaptors. Biochim Biophys Acta. 1998;1404:173-93 pubmed
    ..Genetic studies indicate that AP-3 plays a role in the sorting of proteins to lysosomes and lysosome-related organelles. ..
  3. Checkley M, Luttge B, Freed E. HIV-1 envelope glycoprotein biosynthesis, trafficking, and incorporation. J Mol Biol. 2011;410:582-608 pubmed publisher
    ..Here, we review our current understanding of HIV-1 Env glycoprotein trafficking and incorporation into virions. ..
  4. Berlioz Torrent C, Shacklett B, Erdtmann L, Delamarre L, Bouchaert I, Sonigo P, et al. Interactions of the cytoplasmic domains of human and simian retroviral transmembrane proteins with components of the clathrin adaptor complexes modulate intracellular and cell surface expression of envelope glycoproteins. J Virol. 1999;73:1350-61 pubmed
  5. Ohno H, Tomemori T, Nakatsu F, Okazaki Y, Aguilar R, Foelsch H, et al. Mu1B, a novel adaptor medium chain expressed in polarized epithelial cells. FEBS Lett. 1999;449:215-20 pubmed
    ..Here, we report the identification of a novel member of the adaptor medium chain family, named mu1B, which is closely related to the previously described mu1A (79% amino acid sequence identity)...
  6. FOLSCH H, Ohno H, Bonifacino J, Mellman I. A novel clathrin adaptor complex mediates basolateral targeting in polarized epithelial cells. Cell. 1999;99:189-98 pubmed
    ..We have identified a novel form of the AP-1 clathrin adaptor complex that contains as one of its subunits mu1B, an epithelial cell-specific homolog of the ubiquitously expressed mu1A...
  7. Wyss S, Berlioz Torrent C, Boge M, Blot G, Honing S, Benarous R, et al. The highly conserved C-terminal dileucine motif in the cytosolic domain of the human immunodeficiency virus type 1 envelope glycoprotein is critical for its association with the AP-1 clathrin adaptor [correction of adapter]. J Virol. 2001;75:2982-92 pubmed
    ..Finally, the C-terminal dileucine was shown to assist the membrane-proximal Y712 motif in restricting the cell surface expression of Env. ..
  8. Ohno H, Stewart J, Fournier M, Bosshart H, Rhee I, Miyatake S, et al. Interaction of tyrosine-based sorting signals with clathrin-associated proteins. Science. 1995;269:1872-5 pubmed
    ..The interaction was confirmed by in vitro binding assays. Thus, it is likely that the medium chains serve as signal-binding components of the clathrin-dependent sorting machinery. ..
  9. Shimada T, Kunieda T, Sumi S, Koumoto Y, Tamura K, Hatano K, et al. The AP-1 Complex is Required for Proper Mucilage Formation in Arabidopsis Seeds. Plant Cell Physiol. 2018;59:2331-2338 pubmed publisher
    ..Previously, a loss-of-function mutant of AP1M2, the medium subunit of AP-1, has been shown to display deleterious growth defects because of defective cytokinesis...

More Information


  1. Takahashi D, Hase K, Kimura S, Nakatsu F, Ohmae M, Mandai Y, et al. The epithelia-specific membrane trafficking factor AP-1B controls gut immune homeostasis in mice. Gastroenterology. 2011;141:621-32 pubmed publisher
    ..The role of AP-1B in intestinal immunity was examined in AP-1B-deficient mice (Ap1m2(-/-)) by monitoring their phenotypes, intestinal morphology, and epithelial barrier functions...
  2. Li C, Hao M, Cao Z, Ding W, Graves Deal R, Hu J, et al. Naked2 acts as a cargo recognition and targeting protein to ensure proper delivery and fusion of TGF-alpha containing exocytic vesicles at the lower lateral membrane of polarized MDCK cells. Mol Biol Cell. 2007;18:3081-93 pubmed
    ..Naked2-associated vesicles are delivered to the lower lateral membrane of polarized MDCK cells independent of mu1B adaptin. We identify a basolateral targeting segment within Naked2; residues 1-173 redirect NHERF-1 from the apical ..
  3. Abraham S, Kirkwood R, Laird T, Saputra S, Mitchell T, Singh M, et al. Dissemination and persistence of extended-spectrum cephalosporin-resistance encoding IncI1-blaCTXM-1 plasmid among Escherichia coli in pigs. ISME J. 2018;12:2352-2362 pubmed publisher
    ..ESC resistance identified among E. coli isolates was attributed to the carriage of an IncI1 ST-3 plasmid (pCTXM1-MU2) encoding blaCTXM-1. Genomic characterisation of selected E...
  4. 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...
  5. Luo S, Xin X, Du L, Ye K, Wei Y. Dimerization Mediated by a Divergent Forkhead-associated Domain Is Essential for the DNA Damage and Spindle Functions of Fission Yeast Mdb1. J Biol Chem. 2015;290:21054-66 pubmed publisher
    ..The FHA domain of the Drosophila homolog of MDC1, MU2, also forms a homodimer but utilizes a different dimer interface...
  6. Kiguchi Y, Aono Y, Watanabe Y, Yamamoto Nemoto S, Shimizu K, Shimizu T, et al. In vivo neurochemical evidence that delta1-, delta2- and mu2-opioid receptors, but not mu1-opioid receptors, inhibit acetylcholine efflux in the nucleus accumbens of freely moving rats. Eur J Pharmacol. 2016;789:402-410 pubmed publisher
    ..Delta- and mu-opioid receptors are divided into delta1- and delta2-opioid receptors and mu1- and mu2-opioid receptors, respectively...
  7. Tang Y, Ho S, Tan E, Ng A, McPherson J, Goh G, et al. Functional genomics identifies specific vulnerabilities in PTEN-deficient breast cancer. Breast Cancer Res. 2018;20:22 pubmed publisher
    ..the reproducibility analysis (step 3) identified six candidate broad-spectrum PTEN-SSL genes (PIK3CB, ADAMTS20, AP1M2, HMMR, STK11, and NUAK1)...
  8. Sugimoto H, Sugahara M, FOLSCH H, Koide Y, Nakatsu F, Tanaka N, et al. Differential recognition of tyrosine-based basolateral signals by AP-1B subunit mu1B in polarized epithelial cells. Mol Biol Cell. 2002;13:2374-82 pubmed
    To investigate the importance of tyrosine recognition by the AP-1B clathrin adaptor subunit mu1B for basolateral sorting of integral membrane proteins in polarized epithelial cells, we have produced and characterized a mutant form of mu1B...
  9. Levine D, Healey M, Wright A, Bates D, Linder J, Samal L. Changes in the quality of care during progress from stage 1 to stage 2 of Meaningful Use. J Am Med Inform Assoc. 2017;24:394-397 pubmed publisher
    ..important implications for the new policy, yet the quality of care provided by physicians transitioning from MU1 to MU2 is unknown...
  10. Umeda A, Meyerholz A, Ungewickell E. Identification of the universal cofactor (auxilin 2) in clathrin coat dissociation. Eur J Cell Biol. 2000;79:336-42 pubmed
    ..The cellular distribution of membrane-associated adaptors was unaffected by overexpression of GAK. Our results point to a hsc70/auxilin-based uncoating system as a ubiquitous feature of eukaryotic cells...
  11. Hirst J, Lindsay M, Robinson M. GGAs: roles of the different domains and comparison with AP-1 and clathrin. Mol Biol Cell. 2001;12:3573-88 pubmed
    ..Together with results from other studies, our findings suggest that the GGAs act as monomeric adaptors, with the four domains involved in cargo selection, membrane localization, clathrin binding, and accessory protein recruitment. ..
  12. Santos da Silva E, Mulinge M, Perez Bercoff D. The frantic play of the concealed HIV envelope cytoplasmic tail. Retrovirology. 2013;10:54 pubmed publisher
    ..It also considers the cellular and viral proteins that have been described to interact with the gp41-CT, with a particular focus on subtype-related polymorphisms. ..
  13. Stephens D, Banting G. Specificity of interaction between adaptor-complex medium chains and the tyrosine-based sorting motifs of TGN38 and lgp120. Biochem J. 1998;335 ( Pt 3):567-72 pubmed
    ..Whereas the wild-type version of the cytosolic domain of TGN38 interacts with highest affinity with mu2, we show that the cytosolic domain of lgp120 interacts almost exclusively with mu3A...
  14. Keyel P, Thieman J, Roth R, Erkan E, Everett E, Watkins S, et al. The AP-2 adaptor beta2 appendage scaffolds alternate cargo endocytosis. Mol Biol Cell. 2008;19:5309-26 pubmed publisher
    ..We conclude that ARH and beta-arrestin depend on a privileged beta2 appendage site for proper cargo recruitment to clathrin bud sites. ..
  15. San Martin C, Garri C, Pizarro F, Walter T, Theil E, Nunez M. Caco-2 intestinal epithelial cells absorb soybean ferritin by mu2 (AP2)-dependent endocytosis. J Nutr. 2008;138:659-66 pubmed
    ..The large number of iron atoms in SBFn makes iron transport across the cell membrane a much more efficient event for SBFn than for single iron atoms as heme or ferrous ions. ..
  16. FOLSCH H, Pypaert M, Schu P, Mellman I. Distribution and function of AP-1 clathrin adaptor complexes in polarized epithelial cells. J Cell Biol. 2001;152:595-606 pubmed
    ..expressed AP-1A by exchange of its single 50-kD mu subunit, mu1A, being replaced by the closely related mu1B. Here we show that this substitution is sufficient to couple basolateral plasma membrane proteins, such as a low-..
  17. Wiemuth D, Ke Y, Rohlfs M, McDonald F. Epithelial sodium channel (ENaC) is multi-ubiquitinated at the cell surface. Biochem J. 2007;405:147-55 pubmed
    ..We confirm that ENaC is associated with the mu2 subunit of the AP-2 (adaptor protein 2) clathrin adaptor...
  18. Ling K, Bairstow S, Carbonara C, Turbin D, Huntsman D, Anderson R. Type I gamma phosphatidylinositol phosphate kinase modulates adherens junction and E-cadherin trafficking via a direct interaction with mu 1B adaptin. J Cell Biol. 2007;176:343-53 pubmed
  19. Wang H, Traub L, Weixel K, Hawryluk M, Shah N, Edinger R, et al. Clathrin-mediated endocytosis of the epithelial sodium channel. Role of epsin. J Biol Chem. 2006;281:14129-35 pubmed
    ..These results identify epsin as an accessory protein linking ENaC to the clathrin-based endocytic machinery thereby regulating the activity of this ion channel at the cell surface. ..
  20. Ohka S, Ohno H, Tohyama K, Nomoto A. Basolateral sorting of human poliovirus receptor alpha involves an interaction with the mu1B subunit of the clathrin adaptor complex in polarized epithelial cells. Biochem Biophys Res Commun. 2001;287:941-8 pubmed
    ..Basolateral sorting of hPVRalpha was observed in Madine-Darby canine kidney cells expressing mu1B, but not in LLC-PK1 porcine kidney cells deficient in mu1B...
  21. Roeth J, Williams M, Kasper M, Filzen T, Collins K. HIV-1 Nef disrupts MHC-I trafficking by recruiting AP-1 to the MHC-I cytoplasmic tail. J Cell Biol. 2004;167:903-13 pubmed
    ..In sum, our evidence suggests that binding of AP-1 to the Nef-MHC-I complex is an important step required for inhibition of antigen presentation by HIV. ..
  22. Korolchuk V, Banting G. CK2 and GAK/auxilin2 are major protein kinases in clathrin-coated vesicles. Traffic. 2002;3:428-39 pubmed
    ..The medium subunit of the AP2 adaptor complex (mu2) is not a substrate for CK2, but is phosphorylated by a second kinase that we show to be cyclin G-associated kinase ..
  23. Hirano T, Higa S, Arimitsu J, Naka T, Ogata A, Shima Y, et al. Luteolin, a flavonoid, inhibits AP-1 activation by basophils. Biochem Biophys Res Commun. 2006;340:1-7 pubmed
    ..These results provide a fundamental structure of flavonoids for IL-4 inhibition and demonstrate a novel action of flavonoids that suppresses the activation of AP-1. ..
  24. Hinds D, Buil A, Ziemek D, Martinez Perez A, Malik R, Folkersen L, et al. Genome-wide association analysis of self-reported events in 6135 individuals and 252 827 controls identifies 8 loci associated with thrombosis. Hum Mol Genet. 2016;25:1867-74 pubmed publisher
    ..of expression profiles and expression quantitative trait loci across different tissues suggested SLC44A2, ILF3 and AP1M2 as the three most plausible candidate genes for the chromosome 19 locus, our only genome-wide significant ..
  25. Rohan S, Tu J, Kao J, Mukherjee P, Campagne F, Zhou X, et al. Gene expression profiling separates chromophobe renal cell carcinoma from oncocytoma and identifies vesicular transport and cell junction proteins as differentially expressed genes. Clin Cancer Res. 2006;12:6937-45 pubmed
    ..To compare gene expression profiles of chromophobe renal cell carcinoma (RCC) and benign oncocytoma, aiming at identifying differentially expressed genes...
  26. Park S, Ha B, Choi G, Ryu J, Kim B, Jung C, et al. EHD2 interacts with the insulin-responsive glucose transporter (GLUT4) in rat adipocytes and may participate in insulin-induced GLUT4 recruitment. Biochemistry. 2004;43:7552-62 pubmed
    ..These findings strongly suggest that EHD2 interacts with GLUT4 in rat adipocytes and may play a key role in insulin-induced GLUT4 recruitment to the plasma membrane. ..
  27. Jullien Flores V, Mahe Y, Mirey G, Leprince C, Meunier Bisceuil B, Sorkin A, et al. RLIP76, an effector of the GTPase Ral, interacts with the AP2 complex: involvement of the Ral pathway in receptor endocytosis. J Cell Sci. 2000;113 ( Pt 16):2837-44 pubmed
    ..b>Mu2, the medium chain of the AP2 complex is shown to interact with RLIP76...
  28. 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
    ..We determined the genomic structure of previously cloned murine genes for mu1B (Ap1m2) and its closely related homolog, mu1A (Ap1m1)...
  29. Seaman M, Sowerby P, Robinson M. Cytosolic and membrane-associated proteins involved in the recruitment of AP-1 adaptors onto the trans-Golgi network. J Biol Chem. 1996;271:25446-51 pubmed
    ..These proteins are all candidates for components of the adaptor docking site on the trans-Golgi network membrane. ..