Functional diversity of protein C-termini: more than zipcoding?
The carboxylated (C)-terminus of proteins, which includes the single terminal alpha-carboxyl group and preceding residues, is uniquely positioned to serve as a recognition signature for a variety of cell-biological processes, including protein targeting, subcellular anchoring and the static and dynamic formation of macromolecular complexes. The terminal sequence motifs can be processed by posttranslational modifications, thereby providing a means to increase sequence diversity and to regulate interactions. Several classes of protein domains have been identified that are either designed for or are capable of interacting with protein C-termini - these include PDZ and TPR domains. The interactions between these protein domains and various terminal epitopes play an important role in specifying cell-biological functions. The combination of diversity and the plasticity of the chemistry of C-termini provides mechanisms for spatial and temporal specificity that are exploited by a variety of biological processes, ranging from specifying prokaryotic protein degradation to nucleating mammalian neuronal signaling complexes. Understanding the diverse functions of protein C-termini might also provide an important indexing criterion for functional proteomics.
Chung
Jean Ju
JJ
Dept of Physiology, Johns Hopkins University School of Medicine, 725 N Wolfe Street, Baltimore, MD 21205, USA.
Shikano
Sojin
S
Hanyu
Yoshiro
Y
Li
Min
M
D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D006801:Humans; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals / Q000502:physiology; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*
D021382:Protein Sorting Signals; D011506:Proteins