Seroatlas · Human Serome Atlas

SKP2

S-phase kinase-associated protein 2

Also known as: FBL1, FBXL1, p45, SKP2_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q13309
Gene
SKP2
Ensembl
ENSG00000145604
Chromosome
5
Canonical length
424 aa
Protein class
Cancer-related genes, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Nucleoli,Cytosol

OverviewNCBI Gene

This gene encodes a member of the F-box protein family which is characterized by an approximately 40 amino acid motif, the F-box. The F-box proteins constitute one of the four subunits of ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which function in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes: Fbws containing WD-40 domains, Fbls containing leucine-rich repeats, and Fbxs containing either different protein-protein interaction modules or no recognizable motifs. The protein encoded by this gene belongs to the Fbls class; in addition to an F-box, this protein contains 10 tandem leucine-rich repeats. This protein is an essential element of the cyclin A-CDK2 S-phase kinase. It specifically recognizes phosphorylated cyclin-dependent kinase inhibitor 1B (CDKN1B, also referred to as p27 or KIP1) predominantly in S phase and interacts with S-phase kinase-associated protein 1 (SKP1 or p19). In addition, this gene is established as a protooncogene causally involved in the pathogenesis of lymphomas. Alternative splicing of this gene generates three transcript variants encoding different isoforms. [provided by RefSeq, Jul 2011]

Canonical amino-acid sequenceUniProt

424 residues, UniProt reviewed canonical sequence.

>Q13309|SKP2
     1  MHRKHLQEIP DLSSNVATSF TWGWDSSKTS ELLSGMGVSA LEKEEPDSEN IPQELLSNLG
    61  HPESPPRKRL KSKGSDKDFV IVRRPKLNRE NFPGVSWDSL PDELLLGIFS CLCLPELLKV
   121  SGVCKRWYRL ASDESLWQTL DLTGKNLHPD VTGRLLSQGV IAFRCPRSFM DQPLAEHFSP
   181  FRVQHMDLSN SVIEVSTLHG ILSQCSKLQN LSLEGLRLSD PIVNTLAKNS NLVRLNLSGC
   241  SGFSEFALQT LLSSCSRLDE LNLSWCFDFT EKHVQVAVAH VSETITQLNL SGYRKNLQKS
   301  DLSTLVRRCP NLVHLDLSDS VMLKNDCFQE FFQLNYLQHL SLSRCYDIIP ETLLELGEIP
   361  TLKTLQVFGI VPDGTLQLLK EALPHLQINC SHFTTIARPT IGNKKNQEIW GIKCRLTLQK
   421  PSCL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SKP2 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)
0.34
Highest tissue expression
36 nTPM

Expression across tissuesHPA

Tissue

  • placenta: 36 nTPM
  • thymus: 12 nTPM
  • bone marrow: 11 nTPM
  • liver: 11 nTPM
  • tonsil: 7.7 nTPM
  • esophagus: 7.5 nTPM

Single-cell type

  • extravillous trophoblasts: 278 nCPM
  • migrating cytotrophoblasts: 236 nCPM
  • hepatocytes: 193 nCPM
  • cytotrophoblasts: 177 nCPM
  • syncytiotrophoblasts: 74 nCPM
  • erythrocyte progenitors: 57 nCPM

Immune cell

  • myeloid DC: 14 nTPM
  • eosinophil: 14 nTPM
  • basophil: 9.2 nTPM
  • MAIT T-cell: 6.8 nTPM
  • classical monocyte: 6.6 nTPM
  • naive CD4 T-cell: 6.4 nTPM

Brain region

  • white matter: 13 nTPM
  • cerebral cortex: 11 nTPM
  • cerebellum: 11 nTPM
  • spinal cord: 10 nTPM
  • medulla oblongata: 10 nTPM
  • basal ganglia: 9.7 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)
0.33
gnomAD pLI
0.96
gnomAD missense Z
1.95
DepMap mean gene effect
-0.65
DepMap dependency class
common

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 8% 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 SKP2 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 SKP2 as an antibody target. Whether an autoantibody or antibody against SKP2 could matter depends on whether native SKP2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SKP2 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 SKP2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SKP2. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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