Change of ADP-ribosylation in human kidney T1-cells by various external stimuli

Human kidney T1-cells in culture respond to various externally applied stresses, such as mechanical manipulations, trypsinization combined with agitation and centrifugation, Gamma-irradiation, and hyperthermia, by increasing the ADP-ribosylation (ADPR) of proteins in cytoplasm and nuclei. On the other hand, a strong static magnetic field or gravitational force reduces ADPR of proteins. These responses are easily detected in cells in monolayer, yet are masked when the conventional assay of ADPR is used on cells in suspension. The multitude of stimuli for either increasing or depressing ADPR of proteins including histones suggests a common pathway of triggering ADPR in which cellular membranes may be involved.