Premium
Further evidence for the mitogenic action of urinary trypsin inhibitor
Author(s) -
Manilal Sushila B.,
Scott G. Kenneth
Publication year - 1996
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549600201791
Subject(s) - intracellular , chemistry , trypsin , calcium , biochemistry , microbiology and biotechnology , biology , enzyme , organic chemistry
We have previously shown that urinary trypsin inhibitor (UTI), also known as bikunin, was mitogenic for human fibroblasts at low concentrations, and growth‐inhibitory at higher concentrations, and have identified high‐ and low‐affinity cellular binding sites for this protein. We have now investigated fibroblast proteins which interact with bikunin. Bikunin binds to proteins of about 50K and 250K. The simplest interpretation is that the 50K protein may be a proteinase which is also the low‐affinity bikunin binding site, involved in growth inhibition, and that the larger protein may be responsible for the mitogenic response to bikunin. Inhibitors of intracellular calcium mobilisation also inhibit the mitogenic response to bikunin, and, by the measurement of the efflux of pre‐loaded 45Ca2+, bikunin at mitogenic concentrations can be shown to stimulate calcium mobilisation.