Protein unc-45 homolog A (UNC45A)

Protein unc-45 homolog A (UNC45A) is a highly conserved myosin-interacting chaperone protein belonging to the UCS (UNC-45/CRO1/She4p) family. It acts as a co-chaperone for HSP90, contributing to myosin head folding and potentially to refolding myosin under stress conditions[2][3]. UNC45A is widely expressed except in muscle, distinguishing it from the muscle-specific UNC45B isoform[1]. UNC45A localizes to centrosomes, where it regulates cell cycle progression and proliferation through recruitment and regulation of the checkpoint kinase ChK1 in a manner independent of Hsp90[1]. Knockdown of UNC45A impairs ChK1 activation and centrosomal function, leading to multinucleation, apoptosis, and reduced tumor growth in vivo[1]. UNC45A overexpression is observed in ovarian and breast cancer and is linked to disease progression. The protein is also involved in regulating hormone receptor activity, including progesterone receptors, via HSP90 modulation[3]. Mutations or dysregulation of UNC45A are associated with various diseases, including myopathies, cataracts, and cancer metastasis[2]. No therapeutic drugs are currently known to directly target UNC45A in clinical practice.

Other names

UNC45ASMAP1Unc-45ASMAP-1GC-UNC45GCUNC-45Smooth muscle cell-associated protein 1IRO039700OOHEprotein unc-45 homolog Ageneral cell UNC45unc-45 homolog A