Post-translational modification
A chemical alteration made to a protein after ribosomal synthesis. It can change the protein’s activity, location, stability, or interactions.
Protein phosphorylation: The addition of a phosphate group to a protein, usually on serine, threonine, or tyrosine. Kinases and phosphatases use this reversible mark to regulate protein activity and interactions.
Protein structure: The three-dimensional arrangement of atoms in a protein, including its folded chains and molecular interactions. A modification can stabilize, disrupt, or reshape structural features that control protein function.
Proteomics: The large-scale study of proteins, including their abundance, structures, functions, and interactions. Proteomics methods identify modified proteins and quantify their changing states.
Epigenetics: The study of heritable changes in gene activity that do not arise from changes in DNA sequence. Histone modifications can alter chromatin structure and gene expression.
Protein synthesis: The cellular process of assembling proteins from amino acids using genetic instructions. Ribosomes synthesize the protein; post-translational changes occur after that assembly.
Protein ubiquitination: The covalent attachment of ubiquitin to a protein, often marking it for degradation or changing its activity. Ubiquitin attachment can redirect a modified protein to the proteasome.
Amino acid: An organic molecule that serves as a building block of proteins. Many modifications attach to particular amino-acid side chains or protein termini.
Mass spectrometry: An analytical technique that identifies molecules by measuring the mass-to-charge ratios of their ions. It can locate modification sites and measure changes in protein abundance.
Signal transduction: The process by which cells convert signals into molecular responses. Reversible protein modifications transmit and tune many signaling pathways.
Co-translational modification: A chemical change to a protein that occurs while its polypeptide chain is being synthesized by a ribosome. Its timing distinguishes it from modifications made after synthesis is complete.