Regulates the morphogenesis and endocytosis of caveolae (PubMed:21807942). Lipid-binding protein that is able to promote the tubulation of the phosphatidic acid-containing membranes it preferentially binds. Plays a role in intracellular vesicle-mediated transport. Involved in the endocytosis of cell-surface receptors like the EGF receptor, contributing to its internalization in the absence of EGF stimulus. Homodimer (PubMed:20471395). May form heterooligomers with other PACSINs (PubMed:11082044). Interacts (via NPF motifs) with EHD1 (via EH domain) (PubMed:15930129). Interacts (via NPF motifs) with EHD2 (via EH domain); this interaction probably stabilizes the caveolae (By similarity). Interacts with EHD3 (PubMed:15930129). Interacts (via the SH3 domain) with MICALL1 (By similarity). Interacts with RAC1 (PubMed:21693584). Interacts (via SH3 domain) with DNM1, SYN1, SYNJ1 and WASL (PubMed:11082044). Interacts (via F-BAR domain) with CAV1; this interaction induces membrane tubulation (PubMed:21610094). Interacts with TRPV4 (PubMed:16627472). Detected at the neck of flask-shaped caveolae. Localization to tubular recycling endosomes probably requires interaction with MICALL1 and EHD1. Widely expressed (at protein level). The F-BAR domain forms a coiled coil and mediates membrane-binding and membrane tubulation (PubMed:20188097, PubMed:20471395). Autoinhibition of these functions is mediated by an interaction between the SH3 and F-BAR domains (By similarity). The F-Bar domain also mediates the binding to the cell actin cytoskeleton through the interaction with CAV-1 (PubMed:21610094). Phosphorylated by casein kinase 2 (CK2). Phosphorylation by PKC probably decreases the membrane binding and tubulation capacities of PACSIN2, thereby modulating the lifetime of caveolae (PubMed:26092940). Results in loss of morphologically defined caveolae. Belongs to the PACSIN family.