In an in vivo search of novel partners for perlecan, a major heparan sulfate proteoglycan of
basement membranes and cell surfaces, we identified progranulin, a secreted growth factor,
as a strong interacting protein. Unambiguous interaction, first observed with the yeast two-
hybrid system, was corroborated by co-immunoprecipitation studies using cell-free
transcription/translation and transient cell transfection assays. The interaction of progranulin
with perlecan domain V involved the first two laminin-and epidermal growth factor-like …