ID   FBX21_HUMAN             Reviewed;         628 AA.
AC   O94952; B3KMF0; Q5BJG0; Q9H087;
DT   09-MAY-2003, integrated into UniProtKB/Swiss-Prot.
DT   16-DEC-2008, sequence version 2.
DT   10-JUN-2026, entry version 188.
DE   RecName: Full=F-box only protein 21;
GN   Name=FBXO21; Synonyms=FBX21, KIAA0875;
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 [MRNA] (ISOFORM 2).
RX   PubMed=10531035; DOI=10.1016/s0960-9822(00)80020-2;
RA   Cenciarelli C., Chiaur D.S., Guardavaccaro D., Parks W., Vidal M.,
RA   Pagano M.;
RT   "Identification of a family of human F-box proteins.";
RL   Curr. Biol. 9:1177-1179(1999).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 2).
RC   TISSUE=Brain;
RX   PubMed=10048485; DOI=10.1093/dnares/5.6.355;
RA   Nagase T., Ishikawa K., Suyama M., Kikuno R., Hirosawa M., Miyajima N.,
RA   Tanaka A., Kotani H., Nomura N., Ohara O.;
RT   "Prediction of the coding sequences of unidentified human genes. XII. The
RT   complete sequences of 100 new cDNA clones from brain which code for large
RT   proteins in vitro.";
RL   DNA Res. 5:355-364(1998).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 2).
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   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=16541075; DOI=10.1038/nature04569;
RA   Scherer S.E., Muzny D.M., Buhay C.J., Chen R., Cree A., Ding Y.,
RA   Dugan-Rocha S., Gill R., Gunaratne P., Harris R.A., Hawes A.C.,
RA   Hernandez J., Hodgson A.V., Hume J., Jackson A., Khan Z.M., Kovar-Smith C.,
RA   Lewis L.R., Lozado R.J., Metzker M.L., Milosavljevic A., Miner G.R.,
RA   Montgomery K.T., Morgan M.B., Nazareth L.V., Scott G., Sodergren E.,
RA   Song X.-Z., Steffen D., Lovering R.C., Wheeler D.A., Worley K.C., Yuan Y.,
RA   Zhang Z., Adams C.Q., Ansari-Lari M.A., Ayele M., Brown M.J., Chen G.,
RA   Chen Z., Clerc-Blankenburg K.P., Davis C., Delgado O., Dinh H.H.,
RA   Draper H., Gonzalez-Garay M.L., Havlak P., Jackson L.R., Jacob L.S.,
RA   Kelly S.H., Li L., Li Z., Liu J., Liu W., Lu J., Maheshwari M.,
RA   Nguyen B.-V., Okwuonu G.O., Pasternak S., Perez L.M., Plopper F.J.H.,
RA   Santibanez J., Shen H., Tabor P.E., Verduzco D., Waldron L., Wang Q.,
RA   Williams G.A., Zhang J., Zhou J., Allen C.C., Amin A.G., Anyalebechi V.,
RA   Bailey M., Barbaria J.A., Bimage K.E., Bryant N.P., Burch P.E.,
RA   Burkett C.E., Burrell K.L., Calderon E., Cardenas V., Carter K., Casias K.,
RA   Cavazos I., Cavazos S.R., Ceasar H., Chacko J., Chan S.N., Chavez D.,
RA   Christopoulos C., Chu J., Cockrell R., Cox C.D., Dang M., Dathorne S.R.,
RA   David R., Davis C.M., Davy-Carroll L., Deshazo D.R., Donlin J.E.,
RA   D'Souza L., Eaves K.A., Egan A., Emery-Cohen A.J., Escotto M., Flagg N.,
RA   Forbes L.D., Gabisi A.M., Garza M., Hamilton C., Henderson N.,
RA   Hernandez O., Hines S., Hogues M.E., Huang M., Idlebird D.G., Johnson R.,
RA   Jolivet A., Jones S., Kagan R., King L.M., Leal B., Lebow H., Lee S.,
RA   LeVan J.M., Lewis L.C., London P., Lorensuhewa L.M., Loulseged H.,
RA   Lovett D.A., Lucier A., Lucier R.L., Ma J., Madu R.C., Mapua P.,
RA   Martindale A.D., Martinez E., Massey E., Mawhiney S., Meador M.G.,
RA   Mendez S., Mercado C., Mercado I.C., Merritt C.E., Miner Z.L., Minja E.,
RA   Mitchell T., Mohabbat F., Mohabbat K., Montgomery B., Moore N., Morris S.,
RA   Munidasa M., Ngo R.N., Nguyen N.B., Nickerson E., Nwaokelemeh O.O.,
RA   Nwokenkwo S., Obregon M., Oguh M., Oragunye N., Oviedo R.J., Parish B.J.,
RA   Parker D.N., Parrish J., Parks K.L., Paul H.A., Payton B.A., Perez A.,
RA   Perrin W., Pickens A., Primus E.L., Pu L.-L., Puazo M., Quiles M.M.,
RA   Quiroz J.B., Rabata D., Reeves K., Ruiz S.J., Shao H., Sisson I.,
RA   Sonaike T., Sorelle R.P., Sutton A.E., Svatek A.F., Svetz L.A.,
RA   Tamerisa K.S., Taylor T.R., Teague B., Thomas N., Thorn R.D., Trejos Z.Y.,
RA   Trevino B.K., Ukegbu O.N., Urban J.B., Vasquez L.I., Vera V.A.,
RA   Villasana D.M., Wang L., Ward-Moore S., Warren J.T., Wei X., White F.,
RA   Williamson A.L., Wleczyk R., Wooden H.S., Wooden S.H., Yen J., Yoon L.,
RA   Yoon V., Zorrilla S.E., Nelson D., Kucherlapati R., Weinstock G.,
RA   Gibbs R.A.;
RT   "The finished DNA sequence of human chromosome 12.";
RL   Nature 440:346-351(2006).
RN   [5]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RA   Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., Mobarry C.M.,
RA   Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., Flanigan M.J.,
RA   Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., Hannenhalli S.,
RA   Turner R., Yooseph S., Lu F., Nusskern D.R., Shue B.C., Zheng X.H.,
RA   Zhong F., Delcher A.L., Huson D.H., Kravitz S.A., Mouchard L., Reinert K.,
RA   Remington K.A., Clark A.G., Waterman M.S., Eichler E.E., Adams M.D.,
RA   Hunkapiller M.W., Myers E.W., Venter J.C.;
RL   Submitted (JUL-2005) to the EMBL/GenBank/DDBJ databases.
RN   [6]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 2-628 (ISOFORM 2).
RC   TISSUE=Testis;
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   [7]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 51-628 (ISOFORM 1).
RC   TISSUE=Testis;
RX   PubMed=11230166; DOI=10.1101/gr.gr1547r;
RA   Wiemann S., Weil B., Wellenreuther R., Gassenhuber J., Glassl S.,
RA   Ansorge W., Boecher M., Bloecker H., Bauersachs S., Blum H., Lauber J.,
RA   Duesterhoeft A., Beyer A., Koehrer K., Strack N., Mewes H.-W.,
RA   Ottenwaelder B., Obermaier B., Tampe J., Heubner D., Wambutt R., Korn B.,
RA   Klein M., Poustka A.;
RT   "Towards a catalog of human genes and proteins: sequencing and analysis of
RT   500 novel complete protein coding human cDNAs.";
RL   Genome Res. 11:422-435(2001).
CC   -!- FUNCTION: Substrate-recognition component of the SCF (SKP1-CUL1-F-box
CC       protein)-type E3 ubiquitin ligase complex. {ECO:0000250}.
CC   -!- SUBUNIT: Directly interacts with SKP1 and CUL1. {ECO:0000250}.
CC   -!- INTERACTION:
CC       O94952; Q9Y6B2: EID1; NbExp=7; IntAct=EBI-311435, EBI-1049975;
CC       O94952; P63208: SKP1; NbExp=11; IntAct=EBI-311435, EBI-307486;
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=2;
CC       Name=1;
CC         IsoId=O94952-2; Sequence=Displayed;
CC       Name=2;
CC         IsoId=O94952-1; Sequence=VSP_035975;
CC   -!- MISCELLANEOUS: [Isoform 1]: May be due to a competing acceptor splice
CC       site.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=CAB66833.2; Type=Erroneous termination; Note=Truncated C-terminus.; Evidence={ECO:0000305};
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DR   EMBL; AF174601; AAF04522.1; -; mRNA.
DR   EMBL; AB020682; BAA74898.1; -; mRNA.
DR   EMBL; AK001699; BAG50962.1; -; mRNA.
DR   EMBL; AC026364; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR   EMBL; AC026368; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR   EMBL; CH471054; EAW98105.1; -; Genomic_DNA.
DR   EMBL; BC091496; AAH91496.1; -; mRNA.
DR   EMBL; AL136899; CAB66833.2; ALT_SEQ; mRNA.
DR   CCDS; CCDS44989.1; -. [O94952-1]
DR   CCDS; CCDS9184.1; -. [O94952-2]
DR   RefSeq; NP_055817.1; NM_015002.3. [O94952-1]
DR   RefSeq; NP_296373.1; NM_033624.3. [O94952-2]
DR   AlphaFoldDB; O94952; -.
DR   BioGRID; 116656; 78.
DR   ComplexPortal; CPX-7930; SCF E3 ubiquitin ligase complex, FBXO21 variant.
DR   FunCoup; O94952; 354.
DR   IntAct; O94952; 48.
DR   MINT; O94952; -.
DR   STRING; 9606.ENSP00000328187; -.
DR   GlyGen; O94952; 1 site, 1 O-linked glycan (1 site).
DR   iPTMnet; O94952; -.
DR   PhosphoSitePlus; O94952; -.
DR   BioMuta; FBXO21; -.
DR   jPOST; O94952; -.
DR   MassIVE; O94952; -.
DR   PaxDb; 9606-ENSP00000328187; -.
DR   PeptideAtlas; O94952; -.
DR   ProteomicsDB; 50572; -. [O94952-2]
DR   ProteomicsDB; 50573; -. [O94952-1]
DR   Pumba; O94952; -.
DR   Antibodypedia; 31332; 311 antibodies from 23 providers.
DR   DNASU; 23014; -.
DR   Ensembl; ENST00000330622.9; ENSP00000328187.5; ENSG00000135108.17. [O94952-2]
DR   Ensembl; ENST00000622495.5; ENSP00000483508.1; ENSG00000135108.17. [O94952-1]
DR   GeneID; 23014; -.
DR   KEGG; hsa:23014; -.
DR   MANE-Select; ENST00000622495.5; ENSP00000483508.1; NM_015002.3; NP_055817.1. [O94952-1]
DR   UCSC; uc001twj.4; human. [O94952-2]
DR   AGR; HGNC:13592; -.
DR   ClinPGx; PA28034; -.
DR   CTD; 23014; -.
DR   DisGeNET; 23014; -.
DR   GeneCards; FBXO21; -.
DR   HGNC; HGNC:13592; FBXO21.
DR   HPA; ENSG00000135108; Tissue enhanced (fallopian).
DR   MIM; 609095; gene.
DR   OpenTargets; ENSG00000135108; -.
DR   VEuPathDB; HostDB:ENSG00000135108; -.
DR   eggNOG; ENOG502QS7Z; Eukaryota.
DR   GeneTree; ENSGT00390000005653; -.
DR   InParanoid; O94952; -.
DR   OMA; KQPFYNV; -.
DR   OrthoDB; 28868at2759; -.
DR   PAN-GO; O94952; 0 GO annotations based on evolutionary models.
DR   PhylomeDB; O94952; -.
DR   PathwayCommons; O94952; -.
DR   Reactome; R-HSA-8951664; Neddylation.
DR   Reactome; R-HSA-983168; Antigen processing: Ubiquitination & Proteasome degradation.
DR   SignaLink; O94952; -.
DR   SIGNOR; O94952; -.
DR   Agora; ENSG00000135108; -.
DR   BioGRID-ORCS; 23014; 8 hits in 1194 CRISPR screens.
DR   ChiTaRS; FBXO21; human.
DR   GenomeRNAi; 23014; -.
DR   Pharos; O94952; Tbio.
DR   PRO; PR:O94952; -.
DR   Proteomes; UP000005640; Chromosome 12.
DR   RNAct; O94952; protein.
DR   Bgee; ENSG00000135108; Expressed in corpus epididymis and 207 other cell types or tissues.
DR   ExpressionAtlas; O94952; baseline and differential.
DR   GO; GO:0005829; C:cytosol; TAS:Reactome.
DR   GO; GO:0000151; C:ubiquitin ligase complex; NAS:UniProtKB.
DR   GO; GO:0003677; F:DNA binding; IEA:InterPro.
DR   GO; GO:0004842; F:ubiquitin-protein transferase activity; NAS:UniProtKB.
DR   GO; GO:0031146; P:SCF-dependent proteasomal ubiquitin-dependent protein catabolic process; NAS:ComplexPortal.
DR   GO; GO:0006511; P:ubiquitin-dependent protein catabolic process; NAS:UniProtKB.
DR   CDD; cd22096; F-box_FBXO21; 1.
DR   Gene3D; 1.20.1280.50; -; 1.
DR   Gene3D; 2.30.30.390; Hemimethylated DNA-binding domain; 1.
DR   InterPro; IPR036047; F-box-like_dom_sf.
DR   InterPro; IPR001810; F-box_dom.
DR   InterPro; IPR011722; Hemimethylated_DNA-bd_dom.
DR   InterPro; IPR036623; Hemimethylated_DNA-bd_sf.
DR   InterPro; IPR032698; SirB1_N.
DR   NCBIfam; TIGR02097; yccV; 1.
DR   PANTHER; PTHR31350:SF21; F-BOX ONLY PROTEIN 21; 1.
DR   PANTHER; PTHR31350; SI:DKEY-261L7.2; 1.
DR   Pfam; PF12937; F-box-like; 1.
DR   Pfam; PF13369; Transglut_core2; 1.
DR   Pfam; PF08755; YccV-like; 1.
DR   SMART; SM00992; YccV-like; 1.
DR   SUPFAM; SSF81383; F-box domain; 1.
DR   SUPFAM; SSF141255; YccV-like; 1.
PE   1: Evidence at protein level;
KW   Alternative splicing; Proteomics identification; Reference proteome;
KW   Ubl conjugation pathway.
FT   CHAIN           1..628
FT                   /note="F-box only protein 21"
FT                   /id="PRO_0000119903"
FT   DOMAIN          28..84
FT                   /note="F-box"
FT   VAR_SEQ         442..448
FT                   /note="Missing (in isoform 2)"
FT                   /evidence="ECO:0000303|PubMed:10048485,
FT                   ECO:0000303|PubMed:10531035, ECO:0000303|PubMed:14702039,
FT                   ECO:0000303|PubMed:15489334"
FT                   /id="VSP_035975"
FT   VARIANT         180
FT                   /note="N -> T (in dbSNP:rs11556202)"
FT                   /id="VAR_047919"
SQ   SEQUENCE   628 AA;  72270 MW;  56144BB92D3CE446 CRC64;
     MAAAAVDSAM EVVPALAEEA APEVAGLSCL VNLPGEVLEY ILCCGSLTAA DIGRVSSTCR
     RLRELCQSSG KVWKEQFRVR WPSLMKHYSP TDYVNWLEEY KVRQKAGLEA RKIVASFSKR
     FFSEHVPCNG FSDIENLEGP EIFFEDELVC ILNMEGRKAL TWKYYAKKIL YYLRQQKILN
     NLKAFLQQPD DYESYLEGAV YIDQYCNPLS DISLKDIQAQ IDSIVELVCK TLRGINSRHP
     SLAFKAGESS MIMEIELQSQ VLDAMNYVLY DQLKFKGNRM DYYNALNLYM HQVLIRRTGI
     PISMSLLYLT IARQLGVPLE PVNFPSHFLL RWCQGAEGAT LDIFDYIYID AFGKGKQLTV
     KECEYLIGQH VTAALYGVVN VKKVLQRMVG NLLSLGKREG IDQSYQLLRD SLDLYLAMYP
     DQVQLLLLQA RLYFHLGIWP EKSFCLVLKV LDILQHIQTL DPGQHGAVGY LVQHTLEHIE
     RKKEEVGVEV KLRSDEKHRD VCYSIGLIMK HKRYGYNCVI YGWDPTCMMG HEWIRNMNVH
     SLPHGHHQPF YNVLVEDGSC RYAAQENLEY NVEPQEISHP DVGRYFSEFT GTHYIPNAEL
     EIRYPEDLEF VYETVQNIYS AKKENIDE
//