Seroatlas · Human Serome Atlas

SF3B3

Splicing factor 3B subunit 3

Also known as: KIAA0017, RSE1, SAP130, SF3b130, SF3B3_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession: Q15393
Gene: SF3B3
Ensembl: ENSG00000189091
Chromosome: 16
Canonical length: 1217 aa
Protein class: Plasma proteins, Predicted intracellular proteins
Subcellular location: Nucleoplasm,Nucleoli,Nucleoli rim

OverviewNCBI Gene

This gene encodes subunit 3 of the splicing factor 3b protein complex. Splicing factor 3b, together with splicing factor 3a and a 12S RNA unit, forms the U2 small nuclear ribonucleoproteins complex (U2 snRNP). The splicing factor 3b/3a complex binds pre-mRNA upstream of the intron's branch site in a sequence independent manner and may anchor the U2 snRNP to the pre-mRNA. Splicing factor 3b is also a component of the minor U12-type spliceosome. Subunit 3 has also been identified as a component of the STAGA (SPT3-TAF(II)31-GCN5L acetylase) transcription coactivator-HAT (histone acetyltransferase) complex, and the TFTC (TATA-binding-protein-free TAF(II)-containing complex). These complexes may function in chromatin modification, transcription, splicing, and DNA repair. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

1217 residues, UniProt reviewed canonical sequence.

>Q15393|SF3B3
     1  MFLYNLTLQR ATGISFAIHG NFSGTKQQEI VVSRGKILEL LRPDPNTGKV HTLLTVEVFG
    61  VIRSLMAFRL TGGTKDYIVV GSDSGRIVIL EYQPSKNMFE KIHQETFGKS GCRRIVPGQF
   121  LAVDPKGRAV MISAIEKQKL VYILNRDAAA RLTISSPLEA HKANTLVYHV VGVDVGFENP
   181  MFACLEMDYE EADNDPTGEA AANTQQTLTF YELDLGLNHV VRKYSEPLEE HGNFLITVPG
   241  GSDGPSGVLI CSENYITYKN FGDQPDIRCP IPRRRNDLDD PERGMIFVCS ATHKTKSMFF
   301  FLAQTEQGDI FKITLETDED MVTEIRLKYF DTVPVAAAMC VLKTGFLFVA SEFGNHYLYQ
   361  IAHLGDDDEE PEFSSAMPLE EGDTFFFQPR PLKNLVLVDE LDSLSPILFC QIADLANEDT
   421  PQLYVACGRG PRSSLRVLRH GLEVSEMAVS ELPGNPNAVW TVRRHIEDEF DAYIIVSFVN
   481  ATLVLSIGET VEEVTDSGFL GTTPTLSCSL LGDDALVQVY PDGIRHIRAD KRVNEWKTPG
   541  KKTIVKCAVN QRQVVIALTG GELVYFEMDP SGQLNEYTER KEMSADVVCM SLANVPPGEQ
   601  RSRFLAVGLV DNTVRIISLD PSDCLQPLSM QALPAQPESL CIVEMGGTEK QDELGERGSI
   661  GFLYLNIGLQ NGVLLRTVLD PVTGDLSDTR TRYLGSRPVK LFRVRMQGQE AVLAMSSRSW
   721  LSYSYQSRFH LTPLSYETLE FASGFASEQC PEGIVAISTN TLRILALEKL GAVFNQVAFP
   781  LQYTPRKFVI HPESNNLIII ETDHNAYTEA TKAQRKQQMA EEMVEAAGED ERELAAEMAA
   841  AFLNENLPES IFGAPKAGNG QWASVIRVMN PIQGNTLDLV QLEQNEAAFS VAVCRFSNTG
   901  EDWYVLVGVA KDLILNPRSV AGGFVYTYKL VNNGEKLEFL HKTPVEEVPA AIAPFQGRVL
   961  IGVGKLLRVY DLGKKKLLRK CENKHIANYI SGIQTIGHRV IVSDVQESFI WVRYKRNENQ
  1021  LIIFADDTYP RWVTTASLLD YDTVAGADKF GNICVVRLPP NTNDEVDEDP TGNKALWDRG
  1081  LLNGASQKAE VIMNYHVGET VLSLQKTTLI PGGSESLVYT TLSGGIGILV PFTSHEDHDF
  1141  FQHVEMHLRS EHPPLCGRDH LSFRSYYFPV KNVIDGDLCE QFNSMEPNKQ KNVSEELDRT
  1201  PPEVSKKLED IRTRYAF

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SF3B3 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability: Intracellular
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.22
Highest tissue expression: 25 nTPM

Expression across tissuesHPA

Tissue

tonsil: 25 nTPM
lymph node: 23 nTPM
skeletal muscle: 22 nTPM
thymus: 22 nTPM
bone marrow: 21 nTPM
ovary: 20 nTPM

Single-cell type

esophageal apical cells: 772 nCPM
esophageal suprabasal cells: 147 nCPM
erythrocyte progenitors: 132 nCPM
megakaryocyte progenitors: 105 nCPM
monocyte progenitors: 95 nCPM
suprabasal keratinocytes: 79 nCPM

Immune cell

T-reg: 40 nTPM
MAIT T-cell: 39 nTPM
naive CD4 T-cell: 39 nTPM
total PBMC: 38 nTPM
memory CD8 T-cell: 38 nTPM
gdT-cell: 36 nTPM

Brain region

cerebellum: 50 nTPM
choroid plexus: 42 nTPM
white matter: 41 nTPM
hypothalamus: 38 nTPM
cerebral cortex: 36 nTPM
hippocampal formation: 35 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance): 0.18
gnomAD pLI: 1
gnomAD missense Z: 5.18
DepMap mean gene effect: -2.49
DepMap dependency class: pan

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SF3B3 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SF3B3 as an antibody target. Whether an autoantibody or antibody against SF3B3 could matter depends on whether native SF3B3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SF3B3 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label SF3B3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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