BFSP1

This gene encodes a lens-specific intermediate filament-like protein named filensin. The encoded protein is expressed in lens fiber cells after differentiation has begun. This protein functions as a component of the beaded filament which is a cytoskeletal structure found in lens fiber cells. Mutations in this gene are the cause of autosomal recessive cortical juvenile-onset cataract. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

Beaded Filament Structural Protein 1

Required for the correct formation of lens intermediate filaments as part of a complex composed of BFSP1, BFSP2 and CRYAA (PubMed:28935373).
Involved in altering the calcium regulation of MIP water permeability (PubMed:30790544).

Cell maturation Source: Ensembl
Intermediate filament organization Source: UniProtKB
Lens fiber cell development Source: GO_Central

Cytoskeleton; Cytoplasm; Cell membrane; Cell cortex

Cataract 33, multiple types (CTRCT33): An opacification of the crystalline lens of the eye that frequently results in visual impairment or blindness. Opacities vary in morphology, are often confined to a portion of the lens, and may be static or progressive. In general, the more posteriorly located and dense an opacity, the greater the impact on visual function. CTRCT33 has juvenile-onset and the opacities are restricted to the cortex of the lens, not involving the nucleus.

Proteolytically cleaved during lens cell fiber differentiation with increased fragmentation as fiber cell age increases.
Filensin C-terminal fragment: Myristoylated at Gly-434 following proteolytic cleavage at Asp-433.
Filensin N-terminal fragment: Acetylated at Ala-42 following proteolytic cleavage at Leu-41.