PY-motif-containing plasma membrane (PM) ubiquitin ligase-substrate adaptor; involved in cell wall chitin deposition; ubiquitinates and down-regulates chitin synthase Chs3p abundance at PM via calcineurin/Crz1 signaling pathway which regulates RCR1 expression; delivered to the PM by the exomer complex using a novel bipartite PM sorting motif in the cytoplasmic tail; ubiquitinated; RCR1 has a paralog, RCR2, that arose from the whole genome duplication