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. 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 29 000 to 43 000. 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 possibly other lymphocyte cytoskeletal proteins. Peptide maps of Urocon:11-15 and β and γ actin provide evidence that Urocon:11-15 proteins are closely related to nonmuscle actin, and may be degradation products of this major cytoskeletal protein