PYCR1 Gene - Pyrroline-5-Carboxylate Reductase 1
Key enzyme in proline biosynthesis and mitochondrial function
Gene Information Card
| Symbol | PYCR1 |
|---|---|
| Full Name | Pyrroline-5-Carboxylate Reductase 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 17q25.3 |
| NCBI Gene ID | 5831 ncbi.nlm.nih.gov/gene/5831 |
| Ensembl ID | ENSG00000183091 |
| UniProt ID | P32322 |
| OMIM ID | 179035 |
| HGNC ID | 9721 |
| Aliases | P5CR, PRO3, PYCR, P5C reductase |
Description
PYCR1 encodes pyrroline-5-carboxylate reductase 1, a mitochondrial enzyme that catalyzes the NAD(P)H-dependent reduction of Δ1-pyrroline-5-carboxylate to proline. This reaction is the final step in proline biosynthesis from glutamate. PYCR1 is essential for cellular redox balance, collagen synthesis, and mitochondrial function. Mutations in PYCR1 cause autosomal recessive cutis laxa type 2B (ARCL2B), a disorder characterized by loose, sagging skin, joint laxity, and developmental delay.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Autosomal recessive cutis laxa type 2B (ARCL2B) | Loss-of-function mutations impair proline synthesis, leading to defective collagen and elastic fiber formation | ClinVar, OMIM |
| Cutis laxa with progeroid features | Reduced PYCR1 activity disrupts mitochondrial proline metabolism, contributing to premature aging phenotypes | OMIM |
| Connective tissue disorders | Impaired proline availability affects extracellular matrix integrity | NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.3 | Medium |
| Kidney | 9.8 | Medium |
| Heart | 6.5 | Low |
| Brain | 4.2 | Low |
| Skin | 8.1 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 14.5 | Hepatocellular carcinoma cell line |
| HEK 293 | 11.2 | Embryonic kidney cells |
| HeLa | 7.8 | Cervical cancer cells |
| A549 | 6.3 | Lung carcinoma cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.658C>T (p.Arg220*) | Nonsense | Rare | Loss of function; truncation of protein |
| c.424G>A (p.Gly142Arg) | Missense | Rare | Impaired enzyme activity |
| c.509T>C (p.Leu170Pro) | Missense | Rare | Reduced stability and catalytic function |
Mutation functional classification
Loss of Function (LOF)
Most PYCR1 mutations are loss-of-function, leading to reduced proline biosynthesis and mitochondrial dysfunction.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Not described; recessive inheritance pattern.
View complete mutation data：
Gene Ontology (GO)
| • pyrroline-5-carboxylate reductase activity (GO:0004735) | • proline biosynthetic process (GO:0006561) |
| • mitochondrion (GO:0005739) | • oxidation-reduction process (GO:0055114) |
| • cytosol (GO:0005829) |
Pathways
• Proline biosynthesis from glutamate (Reactome: R-HSA-70614)
• Metabolism of amino acids and derivatives (Reactome: R-HSA-71291)
Protein Summary
PYCR1 is a 319-amino acid mitochondrial enzyme that functions as a homodimer. It uses NAD(P)H to reduce Δ1-pyrroline-5-carboxylate to proline, a critical step in proline synthesis. The enzyme is highly expressed in tissues with high collagen turnover, such as skin and liver. Defects in PYCR1 lead to proline deficiency, mitochondrial stress, and connective tissue abnormalities.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PYCR1 Knockout HEK293 Cell Line | EDJ-KQ3381 | Human | 5831 | Details Get a Quote |
| PYCR1 Knockout A-549 Cell Line | EDJ-KQ25065 | Human | 5831 | Details Get a Quote |
| PYCR1 Knockout HCT 116 Cell Line | EDJ-KQ25066 | Human | 5831 | Details Get a Quote |
| PYCR1 Knockout HeLa Cell Line | EDJ-KQ23678 | Human | 5831 | Details Get a Quote |
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