N-terminal modifications of cellular proteins: The enzymes involved, their substrate specificities and biological effects

作者：Varland Sylvia; O**erg Camilla; Arnesen Thomas^*

来源：Proteomics, 2015, 15(14): 2385-2401.

DOI：10.1002/pmic.201400619

• alpha-amino group
• Acetylation
• Cell biology
• N-terminal
• Protein modification
• Substrate specificity

The vast majority of eukaryotic proteins are N-terminally modified by one or more processing enzymes. Enzymes acting on the very first amino acid of a polypeptide include different peptidases, transferases, and ligases. Methionine aminopeptidases excise the initiator methionine leaving the nascent polypeptide with a newly exposed amino acid that may be further modified. N-terminal acetyl-, methyl-, myristoyl-, and palmitoyltransferases may attach an acetyl, methyl, myristoyl, or palmitoyl group, respectively, to the -amino group of the target protein N-terminus. With the action of ubiquitin ligases, one or several ubiquitin molecules are transferred, and hence, constitute the N-terminal modification. Modifications at protein N-termini represent an important contribution to proteomic diversity and complexity, and are essential for protein regulation and cellular signaling. Consequently, dysregulation of the N-terminal modifying enzymes is implicated in human diseases. We here review the different protein N-terminal modifications occurring co- or post-translationally with emphasis on the responsible enzymes and their substrate specificities.

• 出版日期2015-7