Phosphorylation of Casein by the Lactating Mammary Gland: A Review

Open Access
Publisher Website
Google Scholar
Abstract
The lactating mammary gland [mammalian] synthesizes and secretes large amounts of phosphoproteins that mainly are associated with the casein fraction of milk. The free amino acids and inorganic phosphate of blood serve as building materials for casein, and the final product appears in milk as a colloidal-sized particle, the casein micelle. According to the present concept, the biosynthesis of casein occurs in 2 steps: synthesis of the polypeptide chain, followed by phosphate addition. Phosphate groups are transferred to the nascent casein by a protein kinase localized in the Golgi apparatus. The enzyme uses AID as the phosphate donor and requires divalent cations. Neighboring amino acids may be important in determining which serine residues in casein are phosphorylated. This review discusses historical and current research on the phosphorylation of casein.

This publication has 53 references indexed in Scilit: