CNN3 gene contains 7 exons and encodes calponin 3, a 36.4-kDa protein consisting of 329 amino acids with isoelectric point (pI) of 5.84.

The unique length amino acid sequence of the C-terminal segment of the three calponin isoforms are responsible for their size and overall charge differences.

[9] Calponin 3 is found in the brain with expression in neurons,[10][11] astrocytes,[12] and glial cells,[13] where it may function in regulating the actin cytoskeleton with a proposed role in the plasticity of neural tissues.

Cnn3 knockdown in primary fibroblasts impaired stress fiber formation, resulting in decreased cell motility and contractile ability.

Knockdown or dissociation of calponin 3 from cytoskeleton in response to PKC phosphorylation promoted fusion of trophoblasts.