Lipid-binding protein required for SHH long-range signaling by binding to the dually lipid-modified SHH (ShhNp) and by promoting ShhNp mobilization, solubilization and release from the cell membrane. Acts by enhancing the proteolytic processing (shedding) of the lipid-modified N- and C- terminal of ShhNp at the cell surface. Synergizes with DISP1 to cause an increase in SHH secretion. Probable cell surface coreceptor for VEGFR2 involved in VEGFR2-mediated angiogenesis. Interacts with SHH via the cholesterol anchor of the dually lipid-modified SHH (ShhNp) (By similarity). Interacts with PTCH1 (By similarity). Forms homooligomers and heterooligomers with SCUBE1 and SCUBE3 (By similarity). Interacts with VEGFR2 (By similarity). Secreted and tethered at the cell surface. Expressed in the dorsal neural tube. The CUB domain is important for the interaction with the cholesterol-anchor of SHH. The CUB domain regulates protease recruitment and activation during SHH shedding. N-glycosylated. Zebrafish 'you class' developmental mutants are grouped together based on the anormal U-shaped morphology of the somites. Homozygous zebrafish mutants show disruption of the formation of hedgehog-sensitive muscle fates, with an altered myotomal morphology from a characteristic chevron shape to a more rounded U-shaped. One of these 'you class' mutant results from disruption of the Scube2 gene. These mutants lack slow twitch muscle and muscle pionneer cells, and PTCH1 expression within the myotome and neural tube is essentially absent.