Seroatlas · Human Serome Atlas

TTC21B

Tetratricopeptide repeat protein 21B

Also known as: FAP60, FLA17, FLJ11457, IFT139, IFT139B, JBTS11, NPHP12, THM1, TT21B_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q7Z4L5
Gene
TTC21B
Ensembl
ENSG00000123607
Chromosome
2
Canonical length
1316 aa
Protein class
Disease related genes, Human disease related genes, Predicted intracellular proteins
Subcellular location
Primary cilium,Centriolar satellite,Basal body,Cytosol,Connecting piece,Mid piece,Principal piece,End piece

OverviewNCBI Gene

This gene encodes a member of TTC21 family, containing several tetratricopeptide repeat (TPR) domains. This protein is localized to the cilium axoneme, and may play a role in retrograde intraflagellar transport in cilia. Mutations in this gene are associated with various ciliopathies, nephronophthisis 12, and asphyxiating thoracic dystrophy 4. [provided by RefSeq, Oct 2011]

Canonical amino-acid sequenceUniProt

1316 residues, UniProt reviewed canonical sequence.

>Q7Z4L5|TTC21B
     1  MDSQELKTLI NYYCQERYFH HVLLVASEGI KRYGSDPVFR FYHAYGTLME GKTQEALREF
    61  EAIKNKQDVS LCSLLALIYA HKMSPNPDRE AILESDARVK EQRKGAGEKA LYHAGLFLWH
   121  IGRHDKAREY IDRMIKISDG SKQGHVLKAW LDITRGKEPY TKKALKYFEE GLQDGNDTFA
   181  LLGKAQCLEM RQNYSGALET VNQIIVNFPS FLPAFVKKMK LQLALQDWDQ TVETAQRLLL
   241  QDSQNVEALR MQALYYVCRE GDIEKASTKL ENLGNTLDAM EPQNAQLFYN ITLAFSRTCG
   301  RSQLILQKIQ TLLERAFSLN PQQSEFATEL GYQMILQGRV KEALKWYKTA MTLDETSVSA
   361  LVGFIQCQLI EGQLQDADQQ LEFLNEIQQS IGKSAELIYL HAVLAMKKNK RQEEVINLLN
   421  DVLDTHFSQL EGLPLGIQYF EKLNPDFLLE IVMEYLSFCP MQPASPGQPL CPLLRRCISV
   481  LETVVRTVPG LLQTVFLIAK VKYLSGDIEA AFNNLQHCLE HNPSYADAHL LLAQVYLSQE
   541  KVKLCSQSLE LCLSYDFKVR DYPLYHLIKA QSQKKMGEIA DAIKTLHMAM SLPGMKRIGA
   601  STKSKDRKTE VDTSHRLSIF LELIDVHRLN GEQHEATKVL QDAIHEFSGT SEEVRVTIAN
   661  ADLALAQGDI ERALSILQNV TAEQPYFIEA REKMADIYLK HRKDKMLYIT CFREIAERMA
   721  NPRSFLLLGD AYMNILEPEE AIVAYEQALN QNPKDGTLAS KMGKALIKTH NYSMAITYYE
   781  AALKTGQKNY LCYDLAELLL KLKWYDKAEK VLQHALAHEP VNELSALMED GRCQVLLAKV
   841  YSKMEKLGDA ITALQQAREL QARVLKRVQM EQPDAVPAQK HLAAEICAEI AKHSVAQRDY
   901  EKAIKFYREA LVHCETDNKI MLELARLYLA QDDPDSCLRQ CALLLQSDQD NEAATMMMAD
   961  LMFRKQDYEQ AVFHLQQLLE RKPDNYMTLS RLIDLLRRCG KLEDVPRFFS MAEKRNSRAK
  1021  LEPGFQYCKG LYLWYTGEPN DALRHFNKAR KDRDWGQNAL YNMIEICLNP DNETVGGEVF
  1081  ENLDGDLGNS TEKQESVQLA VRTAEKLLKE LKPQTVQGHV QLRIMENYCL MATKQKSNVE
  1141  QALNTFTEIA ASEKEHIPAL LGMATAYMIL KQTPRARNQL KRIAKMNWNA IDAEEFEKSW
  1201  LLLADIYIQS AKYDMAEDLL KRCLRHNRSC CKAYEYMGYI MEKEQAYTDA ALNYEMAWKY
  1261  SNRTNPAVGY KLAFNYLKAK RYVDSIDICH QVLEAHPTYP KIRKDILDKA RASLRP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against TTC21B 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)
0.25
Highest tissue expression
8.6 nTPM

Expression across tissuesHPA

Tissue

  • tongue: 8.6 nTPM
  • skeletal muscle: 7.1 nTPM
  • retina: 6.9 nTPM
  • cerebellum: 6.1 nTPM
  • ovary: 6.1 nTPM
  • endometrium: 5.8 nTPM

Single-cell type

  • endometrial ciliated cells: 310 nCPM
  • respiratory ciliated cells: 292 nCPM
  • fallopian tube ciliated cells: 257 nCPM
  • epididymal efferent duct ciliated cells: 145 nCPM
  • ependymal cells: 141 nCPM
  • oligodendrocyte progenitor cells: 132 nCPM

Immune cell

  • basophil: 3.2 nTPM
  • NK-cell: 1.4 nTPM
  • naive CD8 T-cell: 1.3 nTPM
  • MAIT T-cell: 1.2 nTPM
  • memory B-cell: 1.2 nTPM
  • memory CD4 T-cell: 1.1 nTPM

Brain region

  • cerebellum: 12 nTPM
  • cerebral cortex: 7.3 nTPM
  • white matter: 6.3 nTPM
  • midbrain: 5.7 nTPM
  • pons: 5.7 nTPM
  • basal ganglia: 5.4 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about TTC21B.

Disease | AllUniProt

Conditions TTC21B is implicated in, by any mechanism.

  • Nephronophthisis 12 (NPHP12) MIM:613820
  • Short-rib thoracic dysplasia 4 with or without polydactyly (SRTD4) MIM:613819
  • Joubert syndrome 11 (JBTS11) MIM:613820

Disease | GeneticClinVar

141 pathogenic / likely-pathogenic of 1,489 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)
0.85
gnomAD pLI
0
gnomAD missense Z
-0.41
DepMap mean gene effect
0.02
DepMap dependency class
selective

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 TTC21B 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 TTC21B as an antibody target. Whether an autoantibody or antibody against TTC21B could matter depends on whether native TTC21B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

TTC21B 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 TTC21B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/TTC21B. 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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