Required specifically for the determination of 3 vulval precursor cell fates P5.p, P6.p and P7.p during late second and early third larval stages; required for basolateral localization of receptor tyrosine kinase let-23. Could have a general but redundant role in development, functioning in diverse cell lineages to control cell fates (PubMed:10359617, PubMed:2159938). Regulates the trafficking of the glr-1 subunit of AMPA-type glutamate receptors (AMPRs) in the ventral nerve cord (PubMed:17671168, PubMed:22252129, PubMed:22213799). This may be partly through interacting with the small GTPase rab-6.2 in its active GTP-bound state (PubMed:22213799). Interacts (via N-terminus) with egl-9 isoform e (via catalytic domain); the interaction regulates its trafficking; the interaction is direct (PubMed:22252129). Interacts with rab-6.2 (in GTP-bound form) (PubMed:22213799). In trans cisternae of Golgi or trans-Golgi network (PubMed:10359617). Localizes to Gogli-associated structures (PubMed:22213799). Partially co-localizes with glr-1 at the synapse (PubMed:17671168). Localizes in endosome-like structures in ventral cord dendrites. During hypoxia, diffused cytoplasmic localization. Localization in the ventral nerve cord is regulated by egl-9 isoform e and cdk-5 (PubMed:22252129). Co-localizes with rab-6.2 in neuronal cell bodies (PubMed:22213799). Co-localizes with rme-8 in puntate structures in neuronal cell bodies and in the intestine (PubMed:22213799). Expressed in vulval epithelial cells and neurons. Expressed throughout development. PDZ protein interaction domains may not be essential for function in vulval induction. Phosphorylated on multiple Ser and Thr residues by cdk-5 which regulates its localization (PubMed:17671168, PubMed:22252129). May be hydroxylated by egl-9 isoform e on multiple Pro residues which may prevent phosphorylation by cdk-5.