This family includes YGR198w (named YPP1, also called alpha-synuclein protective protein 1), which is essential in Saccharomyces cerevisiae. It has also been shown to perform fundamental functions in human and mouse. YPP1 is a cargo-transport protein involved in endocytosis. It interacts with genes involved in protein sorting and secretion, and plays a role in the assembly and recruitment of multiple copies of the kinase into phosphoinositide kinase (PIK) patches at the plasma membrane. It has been found to suppress the toxicity of alpha-synuclein (alpha-syn) mutant (A30P) that is associated with early onset of Parkinson's disease (PD) in humans, but not wild-type or the A53T mutant (also associated with early onset PD).
Jiyao W et al.(2023). "The conserved domain database in 2023.",