AP4M1 explained

AP-4 complex subunit mu-1 is a protein that in humans is encoded by the AP4M1 gene.^{[1] [2] [3]}

Function

This gene encodes a subunit of the heterotetrameric AP-4 complex. The encoded protein belongs to the adaptor complexes medium subunits family. This AP-4 complex is involved in the recognition and sorting of cargo proteins with tyrosine-based motifs from the trans-golgi network to the endosomal-lysosomal system.

Interactions

AP4M1 has been shown to interact with AP4B1.^[4]

Clinical relevance

The AP4-complex-mediated trafficking plays a crucial role in brain development and functioning.^[5] Mutations of the gene cause spastic paraplegia 50, one of the many subtypes of spastic paraplegia.

Further reading

• Stephens DJ, Banting G . Specificity of interaction between adaptor-complex medium chains and the tyrosine-based sorting motifs of TGN38 and lgp120 . Biochem. J. . 335 . Pt 3. 567–72 . 1998 . 9794796 . 10.1042/bj3350567. 1219817 .
• Hirst J, Bright NA, Rous B, Robinson MS . Characterization of a Fourth Adaptor-related Protein Complex . Mol. Biol. Cell . 10 . 8 . 2787–802 . 1999 . 10436028 . 10.1091/mbc.10.8.2787. 25515 .
• Aguilar RC . Signal-binding specificity of the mu4 subunit of the adaptor protein complex AP-4 . J. Biol. Chem. . 276 . 16 . 13145–52 . 2001 . 11139587 . 10.1074/jbc.M010591200 . vanc . Boehm M . Gorshkova I . 3 . Crouch . RJ . Tomita . K . Saito . T . Ohno . H . Bonifacino . JS . free .
• Boehm M, Aguilar RC, Bonifacino JS . Functional and physical interactions of the adaptor protein complex AP-4 with ADP-ribosylation factors (ARFs) . EMBO J. . 20 . 22 . 6265–76 . 2002 . 11707398 . 10.1093/emboj/20.22.6265 . 125733 .
• Simmen T . AP-4 binds basolateral signals and participates in basolateral sorting in epithelial MDCK cells . Nat. Cell Biol. . 4 . 2 . 154–9 . 2002 . 11802162 . 10.1038/ncb745 . vanc . Höning S . Icking A . 3 . Tikkanen . Ritva . Hunziker . Walter . 28781777 .
• Strausberg RL . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . vanc . Feingold EA . Grouse LH . 3 . Derge . JG . Klausner . RD . Collins . FS . Wagner . L . Shenmen . CM . Schuler . GD . 2002PNAS...9916899M . free .
• Scherer SW . Human Chromosome 7: DNA Sequence and Biology . Science . 300 . 5620 . 767–72 . 2003 . 12690205 . 10.1126/science.1083423 . 2882961 . vanc . Cheung J . MacDonald JR . 3 . Osborne . LR . Nakabayashi . K . Herbrick . JA . Carson . AR . Parker-Katiraee . L . Skaug . J . 2003Sci...300..767S .
• Ota T . Complete sequencing and characterization of 21,243 full-length human cDNAs . Nat. Genet. . 36 . 1 . 40–5 . 2004 . 14702039 . 10.1038/ng1285 . vanc . Suzuki Y . Nishikawa T . 3 . Otsuki . Tetsuji . Sugiyama . Tomoyasu . Irie . Ryotaro . Wakamatsu . Ai . Hayashi . Koji . Sato . Hiroyuki . free .

Notes and References

1. Wang X, Kilimann MW . Identification of two new mu-adaptin-related proteins, mu-ARP1 and mu-ARP2 . FEBS Lett . 402 . 1 . 57–61 . Feb 1997 . 9013859 . 10.1016/S0014-5793(96)01500-1 . 81844290 . free .
2. Dell'Angelica EC, Mullins C, Bonifacino JS . AP-4, a novel protein complex related to clathrin adaptors . J Biol Chem . 274 . 11 . 7278–85 . Apr 1999 . 10066790 . 10.1074/jbc.274.11.7278 . free .
3. Web site: Entrez Gene: AP4M1 adaptor-related protein complex 4, mu 1 subunit.
4. Hirst J, Bright NA, Rous B, Robinson MS . Characterization of a fourth adaptor-related protein complex . Mol. Biol. Cell . 10 . 8 . 2787–802 . August 1999 . 10436028 . 25515 . 10.1091/mbc.10.8.2787.
5. Abou Jamra R, Philippe O, Raas-Rothschild A, Eck SH, Graf E, Buchert R, Borck G, Ekici A, Brockschmidt FF, Nöthen MM, Munnich A, Strom TM, Reis A, Colleaux L . Adaptor protein complex 4 deficiency causes severe autosomal-recessive intellectual disability, progressive spastic paraplegia, shy character, and short stature . Am. J. Hum. Genet. . 88 . 6 . 788–95 . June 2011 . 21620353 . 3113253 . 10.1016/j.ajhg.2011.04.019 .