EXOC2: Exocyst Complex Component 2
A key regulator of vesicle trafficking, cell polarity, and cytokinesis, implicated in cancer and ciliopathies.
Gene Information Card
| Symbol | EXOC2 |
|---|---|
| Full Name | Exocyst Complex Component 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 6p25.3 |
| NCBI Gene ID | 55770 ncbi.nlm.nih.gov/gene/55770 |
| Ensembl ID | ENSG00000112685 |
| UniProt ID | Q96KP1 |
| OMIM ID | 615329 |
| HGNC ID | 24968 |
| Aliases | SEC5, SEC5L, SEC5L1, Exo70p, Exo70 |
Description
EXOC2 (Exocyst Complex Component 2), also known as SEC5, is a core subunit of the exocyst complex, an octameric protein complex essential for tethering secretory vesicles to specific sites on the plasma membrane prior to fusion. This process is critical for exocytosis, cell polarity, cell migration, and cytokinesis. EXOC2 directly interacts with other exocyst subunits (e.g., EXOC1, EXOC3) and small GTPases such as RALA and RALB to regulate vesicle docking. The gene is located on chromosome 6p25.3 and is ubiquitously expressed, with highest levels in the brain, kidney, and testis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Colorectal Cancer | EXOC2 overexpression promotes tumor growth and metastasis by enhancing exocyst-mediated delivery of growth factor receptors to the plasma membrane, activating MAPK/ERK signaling. | PMID: 25605246 |
| Breast Cancer | EXOC2 amplification (6p25.3) correlates with poor prognosis; the exocyst complex facilitates invasive migration by targeting matrix metalloproteinases to the leading edge. | PMID: 24755471 |
| Ciliopathies (e.g., Bardet-Biedl syndrome) | EXOC2 interacts with BBS proteins; loss-of-function mutations disrupt ciliary membrane docking, impairing primary cilia formation and signaling. | PMID: 20080638 |
| Hepatocellular Carcinoma | EXOC2 upregulation is associated with increased cell proliferation and invasion via RALA-dependent exocyst activation. | PMID: 28925394 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 18.5 | High |
| Kidney | 15.2 | High |
| Testis | 14.8 | High |
| Lung | 9.3 | Medium |
| Liver | 7.1 | Medium |
| Heart | 6.5 | Medium |
| Pancreas | 4.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 22.1 | High expression; commonly used for exocyst studies |
| HeLa | 15.6 | Moderate; involved in cell migration |
| HepG2 | 12.3 | Moderate; liver cancer model |
| MCF7 | 8.9 | Low; breast cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1246C>T (p.Arg416Trp) | Missense | <0.01% | Unknown; predicted damaging by SIFT |
| c.1873G>A (p.Gly625Arg) | Missense | <0.01% | Unknown; predicted benign by PolyPhen |
| c.2110_2111insA (p.Thr704Asnfs*2) | Frameshift | <0.01% | Loss-of-function; associated with ciliopathy |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations (e.g., p.Thr704Asnfs*2) are predicted to cause loss of exocyst function, impairing vesicle tethering and ciliary assembly.
Gain of Function (GOF)
Amplification of the EXOC2 locus (6p25.3) in cancers leads to increased protein expression, enhancing exocyst-mediated signaling and promoting tumor progression.
Dominant Negative (DN)
Missense mutations in the RALA-binding domain may disrupt exocyst assembly, acting in a dominant-negative manner to inhibit vesicle docking.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Exocyst pathway (Reactome: R-HSA-5620912)
• RAL GTPase signaling (Reactome: R-HSA-9013405)
• Vesicle-mediated transport (Reactome: R-HSA-5653656)
• Insulin secretion (KEGG: hsa04911)
Protein Summary
EXOC2 (SEC5) is a 100 kDa protein that forms part of the exocyst complex, which is essential for polarized exocytosis. It contains a pleckstrin homology (PH) domain and a C-terminal domain that mediates interactions with RAL GTPases and other exocyst subunits. The protein localizes to the plasma membrane, Golgi apparatus, and ciliary base. Post-translational modifications include phosphorylation by CDK1 during mitosis, regulating its role in cytokinesis. EXOC2 is also involved in primary cilia assembly by targeting vesicles to the ciliary base.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| EXOC2 Knockout HEK293 Cell Line | EDJ-KQ51474 | Human | 55770 | Details Get a Quote |
| EXOC2 Knockout HeLa Cell Line | EDJ-KQ56630 | Human | 55770 | Details Get a Quote |
| EXOC2 Knockout A-549 Cell Line | EDJ-KQ65132 | Human | 55770 | Details Get a Quote |
| EXOC2 Knockout HCT 116 Cell Line | EDJ-KQ73572 | Human | 55770 | Details Get a Quote |
