Molecular Principles, Components, Technology, and Concepts: Proteins – Posttranslational Modifications: Key Players in Health and Disease

The modification of proteins by the addition of various chemical groups, a process known as posttranslational modification (PTM), greatly increases protein diversity by providing proteins with a wide variety of chemical modifications. These modifications, which may either be irreversible or dynamically reversible, alter protein structure and can affect activity, cellular localization, and protein–protein interactions – thereby playing important roles in both normal and pathological processes. Here we discuss the most abundant protein PTMs, phosphorylation, glycosylation and acetylation, as well as selected other PTMs, in order to provide a basic understanding of their chemical characteristics and major contributions to cellular function.