Molecular cloning and expression of a novel human cDNA related to the diazepam binding inhibitor

In order to isolate the unidentified autoantigens in autoimmune diabetes, a human pancreatic islet cDNA library was constructed and screened with the sera from the diabetic patients. From the library screening, one clone (DRS -1) that strongly reacted with the sera was isolated. Subsequent sequence a nalysis revealed that the clone was a novel cDNA related to the diazepam bi nding inhibitor. DRS-1 was expressed in most tissues including liver, lung, tonsil, and thymus, in addition to pancreatic islets. DRS-1 was in vitro t ranslated and the recombinant DRS-1 protein was expressed in Escherichia co li and purified. The Size of the in vitro translated or bacterially express ed DRS-1 protein was in agreement with the conceptually translated polypept ide of DRS-1 cDNA. Further studies are required to test whether or not DRS- 1 is a new autoantigen in autoimmune diabetes. (C) 1999 Elsevier Science B. V. All rights reserved.