Regulates the morphogenesis and endocytosis of caveolae (PubMed:22718246). 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 (By similarity). May form heterooligomers with other PACSINs (By similarity). Interacts (via NPF motifs) with EHD1 (via EH domain) (By similarity). Interacts with EHD3 (By similarity). Interacts (via the SH3 domain) with MICALL1 (By similarity). Interacts with RAC1 (By similarity). Interacts (via SH3 domain) with DNM1, SYN1, SYNJ1 and WASL (PubMed:10704453). Interacts with CAV1 (By similarity). Interacts with TRPV4 (By similarity). 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). Isoforms 1/3 are predominantly expressed in heart and in PC-12 cells, a pheochromocytoma cell line (at protein level). Isoforms 2/4 are widely expressed with highest levels in muscle, testis and brain (at protein level). The F-BAR domain forms a coiled coil and mediates membrane-binding and membrane tubulation. In the autoinhibited conformation, interaction with the SH3 domain inhibits membrane tubulation mediated by the F-BAR domain (By similarity). Phosphorylated by casein kinase 2 (CK2) and protein kinase C (PKC). Phosphorylation by PKC probably decreases the membrane binding and tubulation capacities of PACSIN2, thereby modulating the lifetime of caveolae (By similarity). Reduces the density of caveolae. Belongs to the PACSIN family.