Myosin-IXa, also termed 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). Its RA domain is located at its head domain and has the beta-grasp ubiquitin-like fold with unknown function. 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.
Feature 1: key conserved lysine K33, 1 residue position
Conserved feature residue pattern:[KR]
Evidence:
Comment:K33/R (Ub numbering) is one of 7 lysines involved in chain linkage in ubiquitin (K6, K11, K27, K29, K33, K48, or K63, Ub numbering), the other 6 lysines are not conserved in this subfamily; may have other functions
Jiyao W et al.(2023). "The conserved domain database in 2023.",