Prothymosin alpha, a mammalian c-myc-regulated acidic nuclear protein, provokes the decondensation of human chromosomes in vitro

Abstract

Prothymosin (ProT alpha) is an acidic nuclear protein, widely distributed in mammalian cells, whose expression is regulated by c-myc and linked to cell proliferation. ProT alpha interacts with histone H1 via its acidic domain, and its overexpression provokes the unfolding of chromatin fibers. Here we show that incubation of human native metaphase chromosomes with ProT alpha induces their extensive unravelling suggesting a function of this protein in chromosome decondensation.