Two-dimensional analysis of human lymphocyte proteins II. Regulation of lymphocyte proteins by a molecule present in normal human urine.

Lymphocytes cultured with concentrated human urine develop many alterations (Clin. Chem. 27:1327, 1981). New proteins appear ("Urocon" proteins), while others disappear ("Urocof" proteins) from the two-dimensional gel pattern. This paper characterizes a human urinary leukocyte effector protein ("HULEP") that is responsible for the appearance of the Urocon:11-15 proteins in human lymphocytes. The effector molecule, HULEP-1, is a protein with a relative molecular mass in the range of 29000 to 43000. Urocon:11-15 production, cytoskeletal changes in the lymphocyte, and the presence of added HULEP-1 in the cultures are all directly related. This molecule appears to alter the structure of the lymphocyte by degrading actin and possible other lymphocyte cytoskeletal proteins. Peptide maps of Urocon:11-15 and beta and gamma actin provide evidence that Urocon:11-15 proteins are closely related to nonmuscle actin, and may be degradation products of this major cytoskeletal protein.