Seroatlas · Human Serome Atlas

SPEF2

Sperm flagellar protein 2

Also known as: CT122, FLJ23577, KPL2, SPEF2_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q9C093
Gene
SPEF2
Ensembl
ENSG00000152582
Chromosome
5
Canonical length
1822 aa
Protein class
Disease related genes, Human disease related genes, Predicted intracellular proteins
Subcellular location
Nuclear bodies,Primary cilium,Cytosol,Flagellar centriole,Mid piece

OverviewNCBI Gene

Involved in sperm axoneme assembly. Located in cytosol; nuclear body; and sperm flagellum. Implicated in spermatogenic failure 43. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

1822 residues, UniProt reviewed canonical sequence.

>Q9C093|SPEF2
     1  MSEILCQWLN KELKVSRTVS PKSFAKAFSS GYLLGEVLHK FELQDDFSEF LDSRVSSAKL
    61  NNFSRLEPTL NLLGVQFDQN VAHGIITEKP GVATKLLYQL YIALQKKKKS GLTGVEMQTM
   121  QRLTNLRLQN MKSDTFQERL RHMIPRQTDF NLMRITYRFQ EKYKHVKEDL AHLHFEKLER
   181  FQKLKEEQRC FDIEKQYLNR RRQNEIMAKI QAAIIQIPKP ASNRTLKALE AQKMMKKKKE
   241  AEDVADEIKK FEALIKKDLQ AKESASKTSL DTAGQTTTDL LNTYSDDEYI KKIQKRLEED
   301  AFAREQREKR RRKLLMDQLI AHEAQEEAYR EEQLINRLMR QSQQERRIAV QLMHVRHEKE
   361  VLWQNRIFRE KQHEERRLKD FQDALDREAA LAKQAKIDFE EQFLKEKRFH DQIAVERAQA
   421  RYEKHYSVCA EILDQIVDLS TKVADYRMLT NNLIPYKLMH DWKELFFNAK PIYEQASVKT
   481  LPANPSREQL TELEKRDLLD TNDYEEYKNM VGEWALPEEM VDNLPPSNNC ILGHILHRLA
   541  EKSLPPRAES TTPELPSFAV KGCLLGKTLS GKTTILRSLQ KDFPIQILSI DTLVQEAIQA
   601  FHDNEKVSEV LPIQKNDEED ALPVLQEEIK ESQDPQHVFS AGPVSDEVLP ETEGETMLSA
   661  NADKTPKAEE VKSSDSFLKL TTRAQLGAKS EQLLKKGKSI PDVLLVDIIV NAINEIPVNQ
   721  DCILDGFPMT LNQAQLLEEA LTGCNRNLTE VERKKAQKST LAIDPATSKE IPLPSPAFDF
   781  VILLDVSDTS SMSRMNDIIA EELSYKTAHE DISQRVAAEN QDKDGDQNLR DQIQHRIIGF
   841  LDNWPLLEQW FSEPENILIK INAEIDKESL CEKVKEILTT EIAKKKNKVE KKLEEKEAEK
   901  KAAASLAELP LPTPPPAPPP EPEKEKEIHQ SHVASKTPTA KGKPQSEAPH GKQESLQEGK
   961  GKKGETALKR KGSPKGKSSG GKVPVKKSPA DSTDTSPVAI VPQPPKPGSE EWVYVNEPVP
  1021  EEMPLFLVPY WELIENSYIN TIKTVLRHLR EDQHTVLAYL YEIRTSFQEF LKRPDHKQDF
  1081  VAQWQADFNS LPDDLWDDEE TKAELHQRVN DLRDRLWDIC DARKEEAEQE RLDIINESWL
  1141  QDTLGMTMNH FFSLMQAELN RFQDTKRLLQ DYYWGMESKI PVEDNKRFTR IPLVQLDSKD
  1201  NSESQLRIPL VPRISISLET VTPKPKTKSV LKGKMDNSLE NVESNFEADE KLVMDTWQQA
  1261  SLAVSHMVAA EIHQRLMEEE KENQPADPKE KSPQMGANKK VKKEPPKKKQ EDKKPKGKSP
  1321  PMAEATPVIV TTEEIAEIKR KNELRVKIKE EHLAALQFEE IATQFRLELI KTKALALLED
  1381  LVTKVVDVYK LMEKWLGERY LNEMASTEKL TDVARYHIET STKIQNELYL SQEDFFINGN
  1441  IKVFPDPPPS IRPPPVEKEE DGTLTIEQLD SLRDQFLDMA PKGIIGNKAF TDILIDLVTL
  1501  NLGTNNFPSN WMHLTQPELQ ELTSLLTVNS EFVDWRKFLL VTSMPWPIPL EEELLETLQK
  1561  FKAVDKEQLG TITFEQYMQA GLWFTGDEDI KIPENPLEPL PFNRQEHLIE FFFRLFADYE
  1621  KDPPQLDYTQ MLLYFACHPD TVEGVYRALS VAVGTHVFQQ VKASIPSAEK TSSTDAGPAE
  1681  EFPEPEENAA REERKLKDDT EKREQKDEEI PENANNEKMS METLLKVFKG GSEAQDSNRF
  1741  ASHLKIENIY AEGFIKTFQD LGAKNLEPIE VAVLLKHPFI QDLISNYSDY KFPDIKIILQ
  1801  RSEHVQGSDG ERSPSRHTEE KK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SPEF2 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)
0.4
Highest tissue expression
18 nTPM

Expression across tissuesHPA

Tissue

  • choroid plexus: 18 nTPM
  • fallopian tube: 15 nTPM
  • cervix: 12 nTPM
  • endometrium: 10 nTPM
  • retina: 9.5 nTPM
  • parathyroid gland: 8.1 nTPM

Single-cell type

  • ependymal cells: 1,033 nCPM
  • choroid plexus epithelial cells: 772 nCPM
  • respiratory ciliated cells: 713 nCPM
  • fallopian tube ciliated cells: 419 nCPM
  • endometrial ciliated cells: 303 nCPM
  • epididymal efferent duct ciliated cells: 269 nCPM

Immune cell

  • MAIT T-cell: 4 nTPM
  • memory CD8 T-cell: 3.4 nTPM
  • gdT-cell: 3.2 nTPM
  • NK-cell: 3 nTPM
  • naive CD8 T-cell: 2.6 nTPM
  • naive CD4 T-cell: 2.1 nTPM

Brain region

  • choroid plexus: 47 nTPM
  • midbrain: 15 nTPM
  • medulla oblongata: 13 nTPM
  • spinal cord: 10 nTPM
  • hypothalamus: 10 nTPM
  • basal ganglia: 8.2 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SPEF2.

Disease | AllUniProt

Conditions SPEF2 is implicated in, by any mechanism.

Disease | GeneticClinVar

12 pathogenic / likely-pathogenic of 439 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.72
gnomAD pLI
0
gnomAD missense Z
-1.01
DepMap mean gene effect
0.02
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SPEF2 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 SPEF2 as an antibody target. Whether an autoantibody or antibody against SPEF2 could matter depends on whether native SPEF2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SPEF2 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 SPEF2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SPEF2. 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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