Protein phosphokinase reactions in mammalian testis. Stimulatory effects of adenosine 3′:5′-cyclic monophosphate on the phosphorylation of basic proteins

Abstract
The soluble fraction of rat testis homogenates is rich in enzymes catalysing the phosphorylation by ATP of many different proteins. The phosphorylation of certain histones, and also of a homogeneous basic protein from guinea-pig seminal-vesicle secretion, is markedly enhanced by 3′:5′-cyclic AMP. Various factors affecting these reactions as catalysed by partially purified testicular enzyme preparations are described, and their possible physiological significance is discussed.