protein kinase C conserved region 1 (C1 domain) found in unconventional myosin-IXa and similar proteins
Myosin-IXa, also called unconventional myosin-9a (Myo9a), is a single-headed, actin-dependent motor protein of the unconventional myosin IX class. It is expressed in several tissues and is enriched in the brain and testes. Myosin-IXa contains a Ras-associating (RA) domain, a motor domain, a protein kinase C conserved region 1 (C1), and a Rho GTPase activating domain (RhoGAP). Myosin-IXa binds the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) GluA2 subunit, and plays a key role in controlling the molecular structure and function of hippocampal synapses. Moreover, Myosin-IXa functions in epithelial cell morphology and differentiation, such that its knockout mice develop hydrocephalus and kidney dysfunction. Myosin-IXa regulates collective epithelial cell migration by targeting RhoGAP activity to cell-cell junctions. Myosin-IXa negatively regulates Rho GTPase signaling, and functions as a regulator of kidney tubule function. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.
Jiyao W et al.(2023). "The conserved domain database in 2023.",