| Symbol |
FMN2 |
| Full Name |
Formin 2 |
| Chromosome |
1q44 |
| NCBI Gene |
22808 |
| Ensembl |
ENSG00000155906 |
| OMIM |
607023 |
| UniProt |
Q9Y2D5 |
| Diseases |
Cognitive Impairment, Autism Spectrum Disorder, Female Infertility |
| Expression |
Cerebral cortex, Hippocampus, Oocytes, Testis |
FMN2 encodes Formin 2, a member of the Formin family of proteins that nucleate and elongate unbranched actin filaments. Formins are key regulators of the actin cytoskeleton and play essential roles in cellular processes including cell division, migration, and morphogenesis. FMN2 is particularly important in neuronal development and synaptic plasticity.
Formin 2 is a unique formin that:
- Nucleates actin filaments — promotes new filament formation
- Elongates filaments — maintains rapid polymerization at barbed ends
- Bundles filaments — organizes actin into parallel arrays
- Inhibits capping — protects barbed ends from capping proteins
In neurons, FMN2 is critical for:
- Dendritic spine formation — regulates spine morphology and density
- Synaptic plasticity — long-term potentiation (LTP) and depression (LTD)
- Axonal branching — determines axonal complexity
- Neuronal migration — cytoskeletal dynamics during cortical development
FMN2 is essential for:
- Meiosis progression — regulates spindle positioning in oocytes
- Fertilization — actin-based processes in fertilization
- Female fertility — knockout mice are sterile
FMN2 mutations are associated with:
- Intellectual disability — autosomal recessive cognitive impairment
- Autism spectrum disorder — rare variants in some cases
- Developmental delay — impaired neuronal development
The actin regulatory functions of FMN2 are relevant to:
- Alzheimer's disease — synaptic dysfunction and spine loss
- Huntington's disease — mutant huntingtin affects FMN2 localization
- Parkinson's disease — dopaminergic neuron morphology
FMN2 is essential for oocyte meiosis and fertility, with mutations causing:
- Primary ovarian insufficiency
- Repeated IVF failure
- Zhou et al., FMN2 in neuronal morphogenesis (2009)
- Schule et al., FMN2 and intellectual disability (2015)
- Leader et al., FMN2 in synaptic plasticity (2018)
- Formin 2 and neuronal morphogenesis (2018)
- FMN2 in actin polymerization (2019)
- Formin family proteins in brain development (2020)