CTDSP1
CTD Small Phosphatase 1: A Regulator of RNA Polymerase II Transcription and Cell Cycle Progression
Gene Information Card
| Symbol | CTDSP1 |
|---|---|
| Full Name | CTD (carboxy-terminal domain, RNA polymerase II, polypeptide A) small phosphatase 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 2q35 |
| NCBI Gene ID | 58190 ncbi.nlm.nih.gov/gene/58190 |
| Ensembl ID | ENSG00000115977 |
| UniProt ID | Q9GZU7 |
| OMIM ID | 608413 |
| HGNC ID | 16877 |
| Aliases | SCP1, NLIIF, HYA22 |
Description
CTDSP1 encodes a member of the small CTD phosphatase (SCP) family. The protein dephosphorylates the carboxy-terminal domain (CTD) of RNA polymerase II, specifically targeting phosphoserine 5 within the heptapeptide repeat (YSPTSPS). This activity represses transcription by promoting the transition from initiation/early elongation to elongation. CTDSP1 also regulates cell cycle progression and has been implicated in tumor suppression. It is widely expressed in human tissues.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (general) | CTDSP1 may act as a tumor suppressor by repressing transcription of growth-promoting genes; loss of expression or function contributes to oncogenesis. | COSMIC; literature |
| Colorectal cancer | Reduced CTDSP1 expression correlates with poor prognosis; re-expression inhibits cell proliferation. | COSMIC; literature |
| Breast cancer | CTDSP1 downregulation observed in tumor samples; potential role in cell cycle dysregulation. | COSMIC; literature |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Heart | 8.3 | Low |
| Liver | 15.2 | Medium |
| Kidney | 10.1 | Medium |
| Lung | 9.7 | Low |
| Testis | 20.4 | High |
| Colon | 11.8 | Medium |
| Breast | 7.6 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 14.5 | Embryonic kidney; moderate expression |
| HeLa | 11.2 | Cervical carcinoma; moderate expression |
| HCT 116 | 9.8 | Colorectal carcinoma; moderate expression |
| MCF7 | 6.3 | Breast carcinoma; low expression |
| A549 | 8.1 | Lung carcinoma; low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | missense | <0.1% | Likely loss of start codon; predicted loss of function |
| c.214C>T (p.Arg72Trp) | missense | <0.1% | Unknown significance; rare population variant |
| c.487_489del (p.Lys163del) | in-frame deletion | <0.1% | Unknown significance; rare |
Mutation functional classification
Loss of Function (LOF)
CTDSP1 loss-of-function mutations are rare but predicted to reduce phosphatase activity, impairing transcription repression and potentially promoting cell proliferation.
Gain of Function (GOF)
No gain-of-function mutations reported in CTDSP1.
Dominant Negative (DN)
No dominant-negative mutations reported in CTDSP1.
View complete mutation data：
Gene Ontology (GO)
| • phosphoprotein phosphatase activity | • RNA polymerase II CTD heptapeptide repeat phosphatase activity |
| • protein dephosphorylation | • transcription elongation from RNA polymerase II promoter |
| • negative regulation of transcription by RNA polymerase II | • cell cycle |
Pathways
• RNA polymerase II transcription termination
• Dephosphorylation of RNA polymerase II CTD
Protein Summary
CTDSP1 is a 261-amino acid protein (UniProt Q9GZU7) belonging to the haloacid dehalogenase (HAD) superfamily. It contains a conserved DXDXT motif essential for phosphatase activity. The protein localizes to the nucleus and dephosphorylates Ser5 of the RNA polymerase II CTD, facilitating the transition from initiation to elongation. CTDSP1 also interacts with and dephosphorylates other substrates, including p53 and RB1, linking it to cell cycle control and tumor suppression.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CTDSP1 Knockout HEK293 Cell Line | EDJ-KQ13048 | Human | 58190 | Details Get a Quote |
| CTDSP1 Knockout HeLa Cell Line | EDJ-KQ41085 | Human | 58190 | Details Get a Quote |
| CTDSP1 Knockout A-549 Cell Line | EDJ-KQ42320 | Human | 58190 | Details Get a Quote |
| CTDSP1 Knockout HCT 116 Cell Line | EDJ-KQ42321 | Human | 58190 | Details Get a Quote |
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