C1QTNF9
Complement C1q and tumor necrosis factor-related protein 9A
Also known as: AQL1, C1QTNF9A, C1T9A_HUMAN, CTRP9, MGC48915
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- P0C862
- Gene
- C1QTNF9
- Ensembl
- ENSG00000240654
- Chromosome
- 13
- Canonical length
- 333 aa
- Protein class
- Predicted secreted proteins, Transporters
- Secretome location
- Secreted to blood
OverviewNCBI Gene
Enables identical protein binding activity. Predicted to be involved in signal transduction. Predicted to be located in extracellular region. Predicted to be part of collagen trimer. [provided by Alliance of Genome Resources, Jul 2025]
Canonical amino-acid sequenceUniProt
333 residues, UniProt reviewed canonical sequence.
>P0C862|C1QTNF9
1 MRIWWLLLAI EICTGNINSQ DTCRQGHPGI PGNPGHNGLP GRDGRDGAKG DKGDAGEPGR
61 PGSPGKDGTS GEKGERGADG KVEAKGIKGD QGSRGSPGKH GPKGLAGPMG EKGLRGETGP
121 QGQKGNKGDV GPTGPEGPRG NIGPLGPTGL PGPMGPIGKP GPKGEAGPTG PQGEPGVRGI
181 RGWKGDRGEK GKIGETLVLP KSAFTVGLTV LSKFPSSDMP IKFDKILYNE FNHYDTAAGK
241 FTCHIAGVYY FTYHITVFSR NVQVSLVKNG VKILHTKDAY MSSEDQASGG IVLQLKLGDE
301 VWLQVTGGER FNGLFADEDD DTTFTGFLLF SSPLocalizationUniProt · AlphaFold · HPA
Whether an antibody against C1QTNF9 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
- Secreted
- Secreted
- Yes
- Transmembrane segments
- 0
- Mean surface accessibility (rSASA)
- 0.55
- Highest tissue expression
- 7.9 nTPM
Expression across tissuesHPA
Tissue
- skeletal muscle: 7.9 nTPM
- heart muscle: 3.8 nTPM
- tongue: 3.1 nTPM
- adipose tissue: 2.9 nTPM
- skin: 2 nTPM
- colon: 1.5 nTPM
Single-cell type
- vascular endothelial cells: 5.3 nCPM
- early spermatids: 2.3 nCPM
- undifferentiated spermatogonia: 2 nCPM
- late primary spermatocytes: 1.4 nCPM
- late spermatids: 1.3 nCPM
- pdcs: 1.3 nCPM
Immune cell
- basophil: 0 nTPM
- classical monocyte: 0 nTPM
- eosinophil: 0 nTPM
- gdT-cell: 0 nTPM
- intermediate monocyte: 0 nTPM
- MAIT T-cell: 0 nTPM
Brain region
- hippocampal formation: 6.5 nTPM
- hypothalamus: 3.5 nTPM
- basal ganglia: 3.2 nTPM
- cerebellum: 3.2 nTPM
- cerebral cortex: 3.2 nTPM
- white matter: 3.1 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)
- 1.29
- gnomAD pLI
- 0
- gnomAD missense Z
- 0.57
- DepMap mean gene effect
- -0.18
- DepMap dependency class
- selective
Cancer expressionTCGA
Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).
OntologyGO
Molecular functions
Cellular components
Protein domainsUniProt · Pfam · InterPro
KeywordsUniProt
InteractionsUniProt · HPA
Protein binding partners of C1QTNF9 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.
- ADIPOQ
- CTRP9B
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads C1QTNF9 as an antibody target. Whether an autoantibody or antibody against C1QTNF9 could matter depends on whether native C1QTNF9 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
C1QTNF9 is annotated as secreted, so native C1QTNF9 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.
Annotation status
The present source text does not explicitly label C1QTNF9 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
Loading the interactive Seroatlas protein explorer...