CIT: Citron Rho-Interacting Serine/Threonine Kinase
Key regulator of cytokinesis and neurodevelopment
Gene Information Card
| Symbol | CIT |
|---|---|
| Full Name | citron rho-interacting serine/threonine kinase |
| Gene Type | protein-coding |
| Chromosomal Location | 12q24.23 |
| NCBI Gene ID | 11113 ncbi.nlm.nih.gov/gene/11113 |
| Ensembl ID | ENSG00000122966 |
| UniProt ID | O14578 |
| OMIM ID | 605629 |
| HGNC ID | 1985 |
| Aliases | CITRON, STK21, KIAA0949 |
Description
The CIT gene encodes citron kinase, a serine/threonine protein kinase that interacts with Rho family small GTPases. It is critical for cytokinesis, particularly in neural progenitor cells, and plays a role in cell cycle regulation and neurodevelopment. Mutations in CIT are associated with primary microcephaly type 17 (MCPH17) and other neurodevelopmental disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Primary microcephaly 17 (MCPH17) | Loss-of-function mutations impair cytokinesis in neural progenitors, reducing brain size | PMID: 27018473, 27159321 |
| Microcephaly with simplified gyral pattern | Disrupted CIT function leads to abnormal neuronal proliferation and migration | PMID: 27159321 |
| Seizures and intellectual disability | CIT deficiency affects neuronal connectivity and synaptic function | ClinVar: RCV000415827 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | High |
| Testis | 6.8 | Medium |
| Lung | 2.1 | Low |
| Liver | 0.9 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 15.3 | High expression |
| HeLa (cervical carcinoma) | 4.2 | Moderate |
| HEK293 (embryonic kidney) | 2.8 | Low |
| K562 (leukemia) | 0.5 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.144C>A (p.Tyr48*) | Nonsense | Rare | Loss of function; truncation |
| c.2152C>T (p.Arg718Trp) | Missense | Rare | Impaired kinase activity |
| c.3076delC (p.Leu1026Trpfs*12) | Frameshift | Rare | Loss of function; premature stop |
| c.3610G>A (p.Gly1204Arg) | Missense | Rare | Dominant negative effect suspected |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations (e.g., p.Tyr48*, p.Leu1026Trpfs*12) lead to truncated or absent protein, causing cytokinesis failure and microcephaly.
Gain of Function (GOF)
Not reported for CIT; no activating mutations described in literature.
Dominant Negative (DN)
Missense mutations (e.g., p.Gly1204Arg) may interfere with wild-type CIT function, though evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • protein serine/threonine kinase activity (GO:0004674) | • ATP binding (GO:0005524) |
| • cell cycle (GO:0007049) | • cytokinesis (GO:0000910) |
| • regulation of neuron projection development (GO:0010975) | • cell projection organization (GO:0030030) |
Pathways
• Rho GTPase signaling (Reactome: R-HSA-194315)
• Cytokinesis (Reactome: R-HSA-2467813)
• Cell Cycle
• Mitotic (Reactome: R-HSA-69278)
Protein Summary
Citron kinase (UniProt O14578) is a 2027-amino acid protein containing an N-terminal serine/threonine kinase domain, a coiled-coil region, and a C-terminal citron homology domain. It localizes to the midbody during cytokinesis and phosphorylates substrates essential for abscission. In neurons, it regulates dendritic spine morphogenesis and synaptic plasticity.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CIT Knockout HEK293 Cell Line | EDJ-KQ3585 | Human | 11113 | Details Get a Quote |
| CITED2 Knockout HEK293 Cell Line | EDJ-KQ7024 | Human | 10370 | Details Get a Quote |
| CITED4 Knockout HEK293 Cell Line | EDJ-KQ12928 | Human | 163732 | Details Get a Quote |
| CIT Knockout A-549 Cell Line | EDJ-KQ24105 | Human | 11113 | Details Get a Quote |
| CITED4 Knockout A-549 Cell Line | EDJ-KQ42140 | Human | 163732 | Details Get a Quote |
| CITED4 Knockout HeLa Cell Line | EDJ-KQ42141 | Human | 163732 | Details Get a Quote |
| CIT Knockout HCT 116 Cell Line | EDJ-KQ25484 | Human | 11113 | Details Get a Quote |
| CIT Knockout HeLa Cell Line | EDJ-KQ25485 | Human | 11113 | Details Get a Quote |
| CITED2 Knockout A-549 Cell Line | EDJ-KQ30395 | Human | 10370 | Details Get a Quote |
| CITED2 Knockout HCT 116 Cell Line | EDJ-KQ31766 | Human | 10370 | Details Get a Quote |
| CITED2 Knockout HeLa Cell Line | EDJ-KQ31767 | Human | 10370 | Details Get a Quote |
| CITED1 Knockout HEK293 Cell Line | EDJ-KQ50448 | Human | 4435 | Details Get a Quote |
| CITED1 Knockout HeLa Cell Line | EDJ-KQ53903 | Human | 4435 | Details Get a Quote |
| CITED1 Knockout A-549 Cell Line | EDJ-KQ62394 | Human | 4435 | Details Get a Quote |
| CITED1 Knockout HCT 116 Cell Line | EDJ-KQ70863 | Human | 4435 | Details Get a Quote |
