ID   FXL21_SHEEP             Reviewed;         434 AA.
AC   B3FL73; B3FL74;
DT   30-NOV-2010, integrated into UniProtKB/Swiss-Prot.
DT   22-JUL-2008, sequence version 1.
DT   25-MAY-2022, entry version 44.
DE   RecName: Full=F-box/LRR-repeat protein 21;
DE   AltName: Full=F-box and leucine-rich repeat protein 21;
GN   Name=Fbxl21;
OS   Ovis aries (Sheep).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae;
OC   Caprinae; Ovis.
OX   NCBI_TaxID=9940;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS 1 AND 2), FUNCTION, INTERACTION WITH
RP   CRY1, AND TISSUE SPECIFICITY.
RX   PubMed=18953409; DOI=10.1371/journal.pone.0003530;
RA   Dardente H., Mendoza J., Fustin J.M., Challet E., Hazlerigg D.G.;
RT   "Implication of the F-Box Protein FBXL21 in circadian pacemaker function in
RT   mammals.";
RL   PLoS ONE 3:E3530-E3530(2008).
CC   -!- FUNCTION: Substrate-recognition component of the SCF(FBXL21) E3
CC       ubiquitin ligase complex involved in circadian rhythm function. Plays a
CC       key role in the maintenance of both the speed and the robustness of the
CC       circadian clock oscillation. The SCF(FBXL21) complex mainly acts in the
CC       cytosol and mediates ubiquitination of CRY proteins (CRY1 and CRY2),
CC       leading to CRY proteins stabilization. The SCF(FBXL21) complex
CC       counteracts the activity of the SCF(FBXL3) complex and protects CRY
CC       proteins from degradation. Involved in the hypothalamic suprachiasmatic
CC       nucleus (SCN) clock regulating temporal organization of the daily
CC       activities. {ECO:0000269|PubMed:18953409}.
CC   -!- PATHWAY: Protein modification; protein ubiquitination.
CC   -!- SUBUNIT: Part of the SCF (SKP1-CUL1-F-box) E3 ubiquitin-protein ligase
CC       complex SCF(FBXL21) composed of CUL1, SKP1, RBX1 and FBXL21. Interacts
CC       with CRY2 (By similarity). Interacts with CRY1. {ECO:0000250,
CC       ECO:0000269|PubMed:18953409}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm, cytosol {ECO:0000250}. Nucleus
CC       {ECO:0000250}. Note=Mainly localizes in the cytosol. Present at low
CC       level in the nucleus (By similarity). {ECO:0000250}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=2;
CC       Name=1;
CC         IsoId=B3FL73-1; Sequence=Displayed;
CC       Name=2;
CC         IsoId=B3FL73-2; Sequence=VSP_040140, VSP_040141;
CC   -!- TISSUE SPECIFICITY: Expressed in the adenohypophysis, hypothalamus
CC       (especially in the suprachiasmatic nucleus or nuclei, SCN) and pineal,
CC       all neuroendocrine structures associated with timing and homeostasis.
CC       {ECO:0000269|PubMed:18953409}.
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DR   EMBL; EU239380; ABY65115.1; -; mRNA.
DR   EMBL; EU239381; ABY65116.1; -; mRNA.
DR   RefSeq; NP_001123210.1; NM_001129738.1. [B3FL73-1]
DR   AlphaFoldDB; B3FL73; -.
DR   SMR; B3FL73; -.
DR   STRING; 9940.ENSOARP00000015923; -.
DR   GeneID; 100169936; -.
DR   KEGG; oas:100169936; -.
DR   CTD; 26223; -.
DR   eggNOG; KOG1947; Eukaryota.
DR   OrthoDB; 1027299at2759; -.
DR   UniPathway; UPA00143; -.
DR   Proteomes; UP000002356; Unplaced.
DR   GO; GO:0005829; C:cytosol; ISS:UniProtKB.
DR   GO; GO:0005634; C:nucleus; ISS:UniProtKB.
DR   GO; GO:0019005; C:SCF ubiquitin ligase complex; ISS:UniProtKB.
DR   GO; GO:0043153; P:entrainment of circadian clock by photoperiod; ISS:UniProtKB.
DR   GO; GO:0016567; P:protein ubiquitination; ISS:UniProtKB.
DR   GO; GO:0048511; P:rhythmic process; IEA:UniProtKB-KW.
DR   Gene3D; 3.80.10.10; -; 1.
DR   InterPro; IPR036047; F-box-like_dom_sf.
DR   InterPro; IPR001810; F-box_dom.
DR   InterPro; IPR006553; Leu-rich_rpt_Cys-con_subtyp.
DR   InterPro; IPR032675; LRR_dom_sf.
DR   Pfam; PF12937; F-box-like; 1.
DR   SMART; SM00256; FBOX; 1.
DR   SMART; SM00367; LRR_CC; 2.
DR   SUPFAM; SSF81383; SSF81383; 1.
DR   PROSITE; PS50181; FBOX; 1.
PE   1: Evidence at protein level;
KW   Alternative splicing; Biological rhythms; Cytoplasm; Leucine-rich repeat;
KW   Nucleus; Reference proteome; Repeat; Ubl conjugation pathway.
FT   CHAIN           1..434
FT                   /note="F-box/LRR-repeat protein 21"
FT                   /id="PRO_0000401204"
FT   DOMAIN          39..85
FT                   /note="F-box"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00080"
FT   REPEAT          140..165
FT                   /note="LRR 1"
FT   REPEAT          187..213
FT                   /note="LRR 2"
FT   REPEAT          214..239
FT                   /note="LRR 3"
FT   REPEAT          242..265
FT                   /note="LRR 4"
FT   REPEAT          322..347
FT                   /note="LRR 5"
FT   REPEAT          349..374
FT                   /note="LRR 6"
FT   REPEAT          375..400
FT                   /note="LRR 7"
FT   VAR_SEQ         164..171
FT                   /note="SHFVSALT -> TRQWMILL (in isoform 2)"
FT                   /evidence="ECO:0000303|PubMed:18953409"
FT                   /id="VSP_040140"
FT   VAR_SEQ         172..434
FT                   /note="Missing (in isoform 2)"
FT                   /evidence="ECO:0000303|PubMed:18953409"
FT                   /id="VSP_040141"
SQ   SEQUENCE   434 AA;  48967 MW;  71E55751B6E4EC31 CRC64;
     MKRNRLSFMN KVLLSSPAVK QPRLGCCSPL SQAHMRAARL DWGSLPHRVV LCVFQYLPLI
     DRARASSVCR RWNEVFHIPD LWRKFEFELN QSATSYFNST HPDLIQQIIK KHAAHLQYVS
     FKVDSSTESA EAACGILSQL VNCSTQTLGL ISTAKPSFMT MSKSHFVSAL TVLFVNSKSL
     SSIKIEDTPV DDPSLSILVA NNSDTLRRLK MSSCPHVSSD GILCVADHCQ GLRELALNYY
     MLSDELLLAL SNETHVNLEH LRIDVVSENP GQIEFHSIKR QSWDALIKHS PGVNVVMYFF
     LYEEEMETFF KEETPVTHLY FGRSVSKGIL GRLSLNCPRL VELVVCANGI QVIDNELICI
     AEHCKNLTAL GLSECEVSCT AFIEFVRLCG RKLTHLSIME DVLIPDDVCS LDEIHTEVSK
     YLGRIWFPDV MPVW