PARD3: Par-3 Family Cell Polarity Regulator
A key scaffolding protein in cell polarity, tight junction assembly, and asymmetric cell division.
Gene Information Card
| Symbol | PARD3 |
|---|---|
| Full Name | Par-3 Family Cell Polarity Regulator |
| Gene Type | protein-coding |
| Chromosomal Location | 10p11.22 |
| NCBI Gene ID | 56288 ncbi.nlm.nih.gov/gene/56288 |
| Ensembl ID | ENSG00000120162 |
| UniProt ID | Q8TEW0 |
| OMIM ID | 606745 |
| HGNC ID | 16151 |
| Aliases | PAR3, ASIP, PAR-3, PARD3A, PAR3alpha, PAR3beta |
Description
PARD3 encodes a scaffold protein that localizes to tight junctions and is essential for establishing and maintaining apical-basal cell polarity. It interacts with atypical protein kinase C (aPKC) and PAR6 to form the PAR complex, which regulates asymmetric cell division, cell migration, and junctional integrity. PARD3 is widely expressed in epithelial and neuronal tissues.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Loss of PARD3 disrupts tight junctions and promotes epithelial-mesenchymal transition (EMT), contributing to invasion and metastasis. | PMID: 23382219; COSMIC |
| Lung adenocarcinoma | PARD3 downregulation correlates with poor prognosis and increased cell migration via altered polarity signaling. | PMID: 25944712; NCBI Gene |
| Colorectal cancer | Reduced PARD3 expression is associated with loss of cell polarity and tumor progression. | PMID: 27562873; ClinVar |
| Neurodevelopmental disorders | PARD3 variants have been implicated in autism spectrum disorder and intellectual disability through disrupted neuronal polarity. | PMID: 27824329; OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 28.5 | High |
| Kidney | 18.2 | Medium |
| Lung | 12.1 | Medium |
| Breast | 9.8 | Medium |
| Liver | 6.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 15.4 | Cervical cancer cell line |
| A549 | 11.2 | Lung adenocarcinoma cell line |
| MCF7 | 9.7 | Breast cancer cell line |
| HEK293 | 22.1 | Embryonic kidney cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234C>T (p.Arg412*) | Nonsense | <0.1% | Loss of function; truncation of PDZ domain |
| c.567G>A (p.Trp189*) | Nonsense | <0.1% | Loss of function; premature stop |
| c.890A>G (p.Gln297Arg) | Missense | 0.2% | Unknown; predicted benign by ClinVar |
| c.2101_2102insA (p.Thr701fs) | Frameshift | <0.1% | Loss of function; disrupted C-terminal aPKC binding |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations that truncate the protein, removing PDZ domains or the aPKC-binding region, leading to polarity defects.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported in PARD3.
Dominant Negative (DN)
Missense mutations in the PDZ domains may act as dominant negatives by sequestering binding partners, but evidence is limited.
View complete mutation data：
Gene Ontology (GO)
Pathways
• hsa:04530 – Tight junction
• hsa:04390 – Hippo signaling pathway
• hsa:04810 – Regulation of actin cytoskeleton
• hsa:04520 – Adherens junction
Protein Summary
PARD3 is a 1356-amino-acid scaffold protein containing three PDZ domains and a C-terminal aPKC-binding region. It localizes to tight junctions and the apical membrane, where it recruits PAR6 and aPKC to establish polarity. PARD3 also interacts with PTEN, CRB3, and LLGL1 to regulate cell proliferation and migration. Isoforms generated by alternative splicing show tissue-specific expression.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PARD3 Knockout HEK293 Cell Line | EDJ-KQ1341 | Human | 56288 | Details Get a Quote |
| PARD3B Knockout HEK293 Cell Line | EDJ-KQ14680 | Human | 117583 | Details Get a Quote |
| PARD3 Knockout A-549 Cell Line | EDJ-KQ20804 | Human | 56288 | Details Get a Quote |
| PARD3 Knockout HCT 116 Cell Line | EDJ-KQ20805 | Human | 56288 | Details Get a Quote |
| PARD3 Knockout HeLa Cell Line | EDJ-KQ20806 | Human | 56288 | Details Get a Quote |
| PARD3B Knockout A-549 Cell Line | EDJ-KQ44976 | Human | 117583 | Details Get a Quote |
| PARD3B Knockout HeLa Cell Line | EDJ-KQ44977 | Human | 117583 | Details Get a Quote |
| PARD3B Knockout HCT 116 Cell Line | EDJ-KQ74927 | Human | 117583 | Details Get a Quote |
