An antiserum raised against the purified human erythrocyte glucose transporter specifically immunoprecipitated a major protein of Mr36 000 and a minor protein of Mr 58 000 from human pancreatic islets. The biosynthetic incorporation of [35S]methionine into the 36-kDa protein increased 2–3 fold in 16 mM D-glucose with 0.1 mM IBMX as compared to islets incubated in 3 mM D-glucose either with or without IBMX. D-Glucose tested without or with IBMX had no effect on the biosynthesis of the 58-kDa protein. The 36-kDa protein was also detected in rat islets and rat islet tumor cells. It is suggested that this protein may represent a D-glucose and cAMP sensitive component of a glucose transport or glucose binding protein in the pancreatic β-cell.