TNP1: Transition Protein 1
Key regulator of spermatid chromatin condensation and male fertility
Gene Information Card
| Symbol | TNP1 |
|---|---|
| Full Name | Transition Protein 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 2q35 |
| NCBI Gene ID | 7141 ncbi.nlm.nih.gov/gene/7141 |
| Ensembl ID | ENSG00000115977 |
| UniProt ID | P09430 |
| OMIM ID | 190231 |
| HGNC ID | 11948 |
| Aliases | TP1, STP-1 |
Description
TNP1 encodes transition protein 1, a basic nuclear protein that replaces histones during spermiogenesis. It facilitates chromatin condensation and is subsequently replaced by protamines. TNP1 is critical for proper sperm head formation and male fertility.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Male infertility (oligozoospermia, teratozoospermia) | Altered TNP1 expression or mutation disrupts chromatin condensation, leading to abnormal sperm morphology and reduced motility. | ClinVar; OMIM 190231; PMID: 10615129 |
| Spermatogenic failure | Loss-of-function variants impair histone-to-protamine transition, causing spermatid maturation arrest. | NCBI Gene; PMID: 23451118 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 78.2 | High |
| Fallopian tube | 0.3 | Not detected |
| Prostate | 0.2 | Not detected |
| Skin | 0.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Spermatid (round) | High | Major site of expression |
| Spermatid (elongating) | High | Active during chromatin remodeling |
| Spermatozoa | Low | Residual after protamine replacement |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.79C>T (p.Arg27Cys) | Missense | Rare | Altered DNA binding affinity; associated with teratozoospermia |
| c.107G>A (p.Arg36His) | Missense | Rare | Reduced chromatin condensation efficiency |
| c.1A>G (p.Met1Val) | Start loss | Very rare | Complete loss of protein function; severe spermatogenic failure |
Mutation functional classification
Loss of Function (LOF)
Start loss and frameshift mutations abolish TNP1 protein, disrupting histone-to-protamine transition and causing spermatid arrest.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
| • nucleus (GO:0005634) | • nucleosome assembly (GO:0006334) |
| • spermatogenesis (GO:0007283) | • chromatin condensation (GO:0030261) |
| • ATP-dependent chromatin remodeling (GO:0043044) |
Pathways
• Spermatogenesis (REACT:13685)
• Chromatin condensation during spermiogenesis (KEGG: hsa04110)
Protein Summary
Transition protein 1 (TNP1) is a 55-amino acid basic nuclear protein expressed exclusively in post-meiotic spermatids. It binds DNA and facilitates the replacement of histones with protamines, a process essential for sperm chromatin compaction and male fertility. TNP1 contains a central DNA-binding domain rich in arginine and lysine residues.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TNP1 Knockout HEK293 Cell Line | EDJ-KQ15877 | Human | 7141 | Details Get a Quote |
| TNP1 Knockout HeLa Cell Line | EDJ-KQ54682 | Human | 7141 | Details Get a Quote |
| TNP1 Knockout A-549 Cell Line | EDJ-KQ63165 | Human | 7141 | Details Get a Quote |
| TNP1 Knockout HCT 116 Cell Line | EDJ-KQ71639 | Human | 7141 | Details Get a Quote |
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