ID MB12B_HUMAN Reviewed; 319 AA. AC Q9H7P6; Q8N6S7; DT 05-SEP-2006, integrated into UniProtKB/Swiss-Prot. DT 05-SEP-2006, sequence version 2. DT 28-JAN-2026, entry version 154. DE RecName: Full=Multivesicular body subunit 12B; DE AltName: Full=ESCRT-I complex subunit MVB12B; DE AltName: Full=Protein FAM125B; GN Name=MVB12B; Synonyms=C9orf28, FAM125B; OS Homo sapiens (Human). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; OC Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; OC Homo. OX NCBI_TaxID=9606; RN [1] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1). RC TISSUE=Spleen; RX PubMed=14702039; DOI=10.1038/ng1285; RA Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., RA Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., RA Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S., RA Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., RA Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., Sudo H., RA Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., Takahashi M., RA Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., Abe K., Kamihara K., RA Katsuta N., Sato K., Tanikawa M., Yamazaki M., Ninomiya K., Ishibashi T., RA Yamashita H., Murakawa K., Fujimori K., Tanai H., Kimata M., Watanabe M., RA Hiraoka S., Chiba Y., Ishida S., Ono Y., Takiguchi S., Watanabe S., RA Yosida M., Hotuta T., Kusano J., Kanehori K., Takahashi-Fujii A., Hara H., RA Tanase T.-O., Nomura Y., Togiya S., Komai F., Hara R., Takeuchi K., RA Arita M., Imose N., Musashino K., Yuuki H., Oshima A., Sasaki N., RA Aotsuka S., Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., RA Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., RA Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., RA Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., RA Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., Fujimori Y., RA Komiyama M., Tashiro H., Tanigami A., Fujiwara T., Ono T., Yamada K., RA Fujii Y., Ozaki K., Hirao M., Ohmori Y., Kawabata A., Hikiji T., RA Kobatake N., Inagaki H., Ikema Y., Okamoto S., Okitani R., Kawakami T., RA Noguchi S., Itoh T., Shigeta K., Senba T., Matsumura K., Nakajima Y., RA Mizuno T., Morinaga M., Sasaki M., Togashi T., Oyama M., Hata H., RA Watanabe M., Komatsu T., Mizushima-Sugano J., Satoh T., Shirai Y., RA Takahashi Y., Nakagawa K., Okumura K., Nagase T., Nomura N., Kikuchi H., RA Masuho Y., Yamashita R., Nakai K., Yada T., Nakamura Y., Ohara O., RA Isogai T., Sugano S.; RT "Complete sequencing and characterization of 21,243 full-length human RT cDNAs."; RL Nat. Genet. 36:40-45(2004). RN [2] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 2). RC TISSUE=Brain; RX PubMed=15489334; DOI=10.1101/gr.2596504; RG The MGC Project Team; RT "The status, quality, and expansion of the NIH full-length cDNA project: RT the Mammalian Gene Collection (MGC)."; RL Genome Res. 14:2121-2127(2004). RN [3] RP INTERACTION WITH TSG101; VPS28; VPS37B AND VPS37C, IDENTIFICATION IN THE RP ESCRT-I COMPLEX, PHOSPHORYLATION AT SER-46; SER-101; THR-122; THR-204; RP THR-205 AND SER-309, AND IDENTIFICATION BY MASS SPECTROMETRY. RX PubMed=18005716; DOI=10.1016/j.chom.2007.06.003; RA Morita E., Sandrin V., Alam S.L., Eckert D.M., Gygi S.P., Sundquist W.I.; RT "Identification of human MVB12 proteins as ESCRT-I subunits that function RT in HIV budding."; RL Cell Host Microbe 2:41-53(2007). CC -!- FUNCTION: Component of the ESCRT-I complex, a regulator of vesicular CC trafficking process. Required for the sorting of endocytic CC ubiquitinated cargos into multivesicular bodies. CC -!- SUBUNIT: Component of the ESCRT-I complex (endosomal sorting complex CC required for transport I) which consists of TSG101, VPS28, a VPS37 CC protein (VPS37A to -D) and MVB12A or MVB12B in a 1:1:1:1 stoichiometry. CC Interacts with TSG101; the association appears to be mediated by the CC TSG101-VPS37 binary subcomplex. Interacts with VPS28. Interacts with CC VPS37B; the association appears to be mediated by the TSG101-VPS37 CC binary subcomplex. Interacts with VPS37C; the association appears to be CC mediated by the TSG101-VPS37 binary subcomplex. CC {ECO:0000269|PubMed:18005716}. CC -!- INTERACTION: CC Q9H7P6; Q8TBB1: LNX1; NbExp=3; IntAct=EBI-6149062, EBI-739832; CC Q9H7P6; A6NJ78: METTL15; NbExp=2; IntAct=EBI-6149062, EBI-10742528; CC -!- SUBCELLULAR LOCATION: Endosome {ECO:0000305}. Late endosome membrane CC {ECO:0000305}; Peripheral membrane protein {ECO:0000305}. CC -!- ALTERNATIVE PRODUCTS: CC Event=Alternative splicing; Named isoforms=2; CC Name=1; CC IsoId=Q9H7P6-1; Sequence=Displayed; CC Name=2; CC IsoId=Q9H7P6-2; Sequence=VSP_020364; CC -!- SIMILARITY: Belongs to the MVB12 family. {ECO:0000305}. CC -!- SEQUENCE CAUTION: CC Sequence=BAB15722.1; Type=Erroneous initiation; Evidence={ECO:0000305}; CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; AK024432; BAB15722.1; ALT_INIT; mRNA. DR EMBL; BC028675; AAH28675.1; -; mRNA. DR CCDS; CCDS35142.1; -. [Q9H7P6-1] DR CCDS; CCDS48022.1; -. [Q9H7P6-2] DR RefSeq; NP_001011703.1; NM_001011703.3. [Q9H7P6-2] DR RefSeq; NP_258257.1; NM_033446.3. [Q9H7P6-1] DR PDB; 3TOW; X-ray; 1.34 A; A=47-192. DR PDBsum; 3TOW; -. DR AlphaFoldDB; Q9H7P6; -. DR SMR; Q9H7P6; -. DR BioGRID; 124621; 21. DR ComplexPortal; CPX-7146; ESCRT-I complex, VPS37A-MVB12B variant. [Q9H7P6-1] DR ComplexPortal; CPX-7164; ESCRT-I complex, VPS37B-MVB12B variant. [Q9H7P6-1] DR ComplexPortal; CPX-7166; ESCRT-I complex, VPS37C-MVB12B variant. [Q9H7P6-1] DR ComplexPortal; CPX-7167; ESCRT-I complex, VPS37D-MVB12B variant. [Q9H7P6-1] DR CORUM; Q9H7P6; -. DR FunCoup; Q9H7P6; 1212. DR IntAct; Q9H7P6; 16. DR STRING; 9606.ENSP00000354772; -. DR GlyGen; Q9H7P6; 2 sites, 1 O-linked glycan (1 site). DR iPTMnet; Q9H7P6; -. DR MetOSite; Q9H7P6; -. DR PhosphoSitePlus; Q9H7P6; -. DR SwissPalm; Q9H7P6; -. DR BioMuta; MVB12B; -. DR DMDM; 114149296; -. DR jPOST; Q9H7P6; -. DR MassIVE; Q9H7P6; -. DR PaxDb; 9606-ENSP00000354772; -. DR PeptideAtlas; Q9H7P6; -. DR ProteomicsDB; 81133; -. [Q9H7P6-1] DR ProteomicsDB; 81134; -. [Q9H7P6-2] DR Pumba; Q9H7P6; -. DR Antibodypedia; 56615; 22 antibodies from 10 providers. DR DNASU; 89853; -. DR Ensembl; ENST00000361171.8; ENSP00000354772.3; ENSG00000196814.16. [Q9H7P6-1] DR Ensembl; ENST00000489637.3; ENSP00000485994.1; ENSG00000196814.16. [Q9H7P6-2] DR GeneID; 89853; -. DR KEGG; hsa:89853; -. DR MANE-Select; ENST00000361171.8; ENSP00000354772.3; NM_033446.3; NP_258257.1. DR UCSC; uc004bqh.3; human. [Q9H7P6-1] DR AGR; HGNC:23368; -. DR ClinPGx; PA162385827; -. DR CTD; 89853; -. DR DisGeNET; 89853; -. DR GeneCards; MVB12B; -. DR HGNC; HGNC:23368; MVB12B. DR HPA; ENSG00000196814; Tissue enriched (brain). DR OpenTargets; ENSG00000196814; -. DR VEuPathDB; HostDB:ENSG00000196814; -. DR eggNOG; KOG4000; Eukaryota. DR GeneTree; ENSGT00940000155945; -. DR HOGENOM; CLU_064823_1_0_1; -. DR InParanoid; Q9H7P6; -. DR OMA; CFCLKRG; -. DR OrthoDB; 6021306at2759; -. DR PAN-GO; Q9H7P6; 5 GO annotations based on evolutionary models. DR PhylomeDB; Q9H7P6; -. DR PathwayCommons; Q9H7P6; -. DR Reactome; R-HSA-162588; Budding and maturation of HIV virion. DR Reactome; R-HSA-174490; Membrane binding and targetting of GAG proteins. DR Reactome; R-HSA-917729; Endosomal Sorting Complex Required For Transport (ESCRT). DR Reactome; R-HSA-9610379; HCMV Late Events. DR Reactome; R-HSA-9615710; Late endosomal microautophagy. DR SignaLink; Q9H7P6; -. DR Agora; ENSG00000196814; -. DR BioGRID-ORCS; 89853; 10 hits in 1139 CRISPR screens. DR ChiTaRS; MVB12B; human. DR EvolutionaryTrace; Q9H7P6; -. DR GenomeRNAi; 89853; -. DR Pharos; Q9H7P6; Tbio. DR PRO; PR:Q9H7P6; -. DR Proteomes; UP000005640; Chromosome 9. DR RNAct; Q9H7P6; protein. DR Bgee; ENSG00000196814; Expressed in C1 segment of cervical spinal cord and 147 other cell types or tissues. DR ExpressionAtlas; Q9H7P6; baseline and differential. DR GO; GO:0005829; C:cytosol; IDA:UniProtKB. DR GO; GO:0005769; C:early endosome; IDA:UniProtKB. DR GO; GO:0010008; C:endosome membrane; TAS:Reactome. DR GO; GO:0000813; C:ESCRT I complex; IDA:UniProtKB. DR GO; GO:0070062; C:extracellular exosome; HDA:UniProtKB. DR GO; GO:0005770; C:late endosome; IDA:UniProtKB. DR GO; GO:0031902; C:late endosome membrane; IEA:UniProtKB-SubCell. DR GO; GO:0005634; C:nucleus; IDA:UniProtKB. DR GO; GO:0005886; C:plasma membrane; IDA:UniProtKB. DR GO; GO:0031982; C:vesicle; IDA:UniProtKB. DR GO; GO:0008289; F:lipid binding; IMP:UniProtKB. DR GO; GO:0090148; P:membrane fission; NAS:ComplexPortal. DR GO; GO:0036258; P:multivesicular body assembly; NAS:ComplexPortal. DR GO; GO:0015031; P:protein transport; IEA:UniProtKB-KW. DR GO; GO:0043328; P:protein transport to vacuole involved in ubiquitin-dependent protein catabolic process via the multivesicular body sorting pathway; NAS:ComplexPortal. DR GO; GO:0042058; P:regulation of epidermal growth factor receptor signaling pathway; IMP:UniProtKB. DR GO; GO:0043162; P:ubiquitin-dependent protein catabolic process via the multivesicular body sorting pathway; IC:UniProtKB. DR GO; GO:0046755; P:viral budding; IMP:UniProtKB. DR GO; GO:0019075; P:virus maturation; IMP:UniProtKB. DR FunFam; 2.100.10.50:FF:000002; Multivesicular body subunit 12B; 1. DR Gene3D; 2.100.10.50; -; 1. DR InterPro; IPR023341; MABP. DR InterPro; IPR018798; MVB12A/B. DR InterPro; IPR040297; MVB12B. DR InterPro; IPR023340; UMA. DR PANTHER; PTHR31547; MULTIVESICULAR BODY SUBUNIT 12B; 1. DR PANTHER; PTHR31547:SF1; MULTIVESICULAR BODY SUBUNIT 12B; 1. DR Pfam; PF10240; DUF2464; 1. DR PROSITE; PS51498; MABP; 1. DR PROSITE; PS51497; UMA; 1. PE 1: Evidence at protein level; KW 3D-structure; Alternative splicing; Endosome; Membrane; Phosphoprotein; KW Protein transport; Proteomics identification; Reference proteome; KW Transport. FT CHAIN 1..319 FT /note="Multivesicular body subunit 12B" FT /id="PRO_0000249074" FT DOMAIN 47..193 FT /note="MABP" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00831" FT DOMAIN 254..303 FT /note="UMA" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00830" FT REGION 1..50 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT REGION 195..222 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT REGION 299..319 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 13..24 FT /note="Pro residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 200..216 FT /note="Low complexity" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT MOD_RES 46 FT /note="Phosphoserine" FT /evidence="ECO:0000269|PubMed:18005716" FT MOD_RES 101 FT /note="Phosphoserine" FT /evidence="ECO:0000269|PubMed:18005716" FT MOD_RES 122 FT /note="Phosphothreonine" FT /evidence="ECO:0000269|PubMed:18005716" FT MOD_RES 204 FT /note="Phosphothreonine" FT /evidence="ECO:0000269|PubMed:18005716" FT MOD_RES 205 FT /note="Phosphothreonine" FT /evidence="ECO:0000269|PubMed:18005716" FT MOD_RES 224 FT /note="Phosphoserine" FT /evidence="ECO:0000250|UniProtKB:Q6KAU4" FT MOD_RES 309 FT /note="Phosphoserine" FT /evidence="ECO:0000269|PubMed:18005716" FT VAR_SEQ 222..319 FT /note="Missing (in isoform 2)" FT /evidence="ECO:0000303|PubMed:15489334" FT /id="VSP_020364" FT STRAND 52..58 FT /evidence="ECO:0007829|PDB:3TOW" FT STRAND 93..97 FT /evidence="ECO:0007829|PDB:3TOW" FT HELIX 105..107 FT /evidence="ECO:0007829|PDB:3TOW" FT STRAND 109..118 FT /evidence="ECO:0007829|PDB:3TOW" FT TURN 134..136 FT /evidence="ECO:0007829|PDB:3TOW" FT STRAND 142..152 FT /evidence="ECO:0007829|PDB:3TOW" FT HELIX 153..155 FT /evidence="ECO:0007829|PDB:3TOW" FT STRAND 159..167 FT /evidence="ECO:0007829|PDB:3TOW" FT STRAND 176..182 FT /evidence="ECO:0007829|PDB:3TOW" FT STRAND 185..192 FT /evidence="ECO:0007829|PDB:3TOW" SQ SEQUENCE 319 AA; 35620 MW; 246E851D0C85D871 CRC64; MRSCFCVRRS RDPPPPQPPP PPPQRGTDQS TMPEVKDLSE ALPETSMDPI TGVGVVASRN RAPTGYDVVA QTADGVDADL WKDGLFKSKV TRYLCFTRSF SKENSHLGNV LVDMKLIDIK DTLPVGFIPI QETVDTQEVA FRKKRLCIKF IPRDSTEAAI CDIRIMGRTK QAPPQYTFIG ELNSMGIWYR MGRVPRNHDS SQPTTPSQSS AASTPAPNLP RHISLTLPAT FRGRNSTRTD YEYQHSNLYA ISAMDGVPFM ISEKFSCVPE SMQPFDLLGI TIKSLAEIEK EYEYSFRTEQ SAAARLPPSP TRCQQIPQS //