Carrier protein that may be involved in membrane-trafficking events associated with cell plate formation during cytokinesis. Binds to some hydrophobic molecules such as phosphoinositides and promotes their transfer between the different cellular sites (By similarity). Interacts with the deubiquitinating enzyme AMSH3. Mainly membrane-associated. Also cytoplasmic (By similarity). 'Patella' means 'small plate' in Latin. Belongs to the patellin family.