MPP3 Gene - Membrane Palmitoylated Protein 3
A member of the MAGUK family involved in cell junction organization and signaling
Gene Information Card
| Symbol | MPP3 |
|---|---|
| Full Name | Membrane palmitoylated protein 3 |
| Gene Type | Protein coding |
| Chromosomal Location | 17q21.31 |
| NCBI Gene ID | 4356 ncbi.nlm.nih.gov/gene/4356 |
| Ensembl ID | ENSG00000141510 |
| UniProt ID | Q13368 |
| OMIM ID | 602996 |
| HGNC ID | 7221 |
| Aliases | MAGUK p55 subfamily member 3, DLG3, CASK-interacting protein 1 |
Description
MPP3 (Membrane Palmitoylated Protein 3) encodes a member of the membrane-associated guanylate kinase (MAGUK) family. The protein contains PDZ, SH3, and guanylate kinase domains and localizes to cell junctions, particularly tight junctions. It plays a role in cell polarity, signal transduction, and cytoskeletal organization. MPP3 interacts with other MAGUK proteins and is involved in the assembly of junctional complexes.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Altered expression may disrupt cell polarity and promote invasion | COSMIC; PMID: 23455423 |
| Colorectal cancer | Downregulation associated with loss of tight junction integrity | COSMIC; PMID: 25691885 |
| Hepatocellular carcinoma | Reduced expression correlates with poor prognosis | PMID: 27573519 |
| Retinitis pigmentosa | Mutations in MPP3 linked to retinal degeneration | OMIM: 602996; PMID: 20046839 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Kidney | 12.5 | Medium |
| Liver | 8.3 | Low |
| Lung | 15.2 | Medium |
| Breast | 6.7 | Low |
| Colon | 10.1 | Medium |
| Retina | 45.0 | High |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 18.4 | Embryonic kidney cells |
| HeLa | 9.2 | Cervical cancer cells |
| MCF7 | 5.8 | Breast cancer cells |
| HepG2 | 7.1 | Liver cancer cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.487C>T (p.Arg163Trp) | Missense | 0.02% | May affect PDZ domain function |
| c.1024G>A (p.Gly342Ser) | Missense | 0.01% | Unknown significance |
| c.1357_1358del (p.Leu453fs) | Frameshift | 0.005% | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift mutations (e.g., p.Leu453fs) predicted to truncate the protein, disrupting guanylate kinase domain and junctional localization.
Gain of Function (GOF)
No gain-of-function mutations reported in MPP3.
Dominant Negative (DN)
Missense mutations in PDZ domain (e.g., p.Arg163Trp) may interfere with protein-protein interactions, potentially acting in a dominant-negative manner.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Tight junction pathway (KEGG: hsa04530)
• Cell adhesion molecules (CAMs) (KEGG: hsa04514)
• MAGUK signaling pathway
Protein Summary
MPP3 is a 585-amino acid protein with a molecular weight of approximately 65 kDa. It contains an N-terminal PDZ domain, an SH3 domain, and a C-terminal guanylate kinase (GUK) domain. The protein is palmitoylated, which facilitates membrane targeting. MPP3 localizes to tight junctions in epithelial cells and interacts with CASK, DLG1, and other MAGUK proteins. It is involved in maintaining cell polarity and barrier function. Expression is highest in retina, kidney, and lung.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MPP3 Knockout HEK293 Cell Line | EDJ-KQ5237 | Human | 4356 | Details Get a Quote |
| MPP3 Knockout A-549 Cell Line | EDJ-KQ28265 | Human | 4356 | Details Get a Quote |
| MPP3 Knockout HCT 116 Cell Line | EDJ-KQ28266 | Human | 4356 | Details Get a Quote |
| MPP3 Knockout HeLa Cell Line | EDJ-KQ28267 | Human | 4356 | Details Get a Quote |
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