Functional diversity of protein C-termini: more than zipcoding?

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• The carboxylated (C)-terminus of proteins, comprising the alpha-carboxyl group and adjacent residues, is crucial for cellular recognition.
• This terminal region participates in vital processes such as protein targeting, subcellular anchoring, and the assembly of macromolecular complexes.

Purpose of the Study:

• To explore the diverse roles of protein C-termini in cellular functions.
• To highlight the significance of C-terminal sequence motifs and their interactions with specific protein domains.

Main Methods:

• Review of existing literature on protein C-termini and their interacting domains.
• Analysis of posttranslational modifications affecting C-terminal sequences.
• Examination of the functional implications of C-terminal interactions in various biological systems.

Main Results:

• Protein C-termini serve as versatile recognition signatures for numerous cell-biological processes.
• Posttranslational modifications of C-termini enhance sequence diversity and regulate molecular interactions.
• Domains such as PDZ and TPR specifically recognize and interact with protein C-termini, mediating critical cellular functions.

Conclusions:

• The plasticity and diversity of C-termini enable precise spatial and temporal regulation of biological processes.
• Understanding C-terminal functions is essential for comprehending processes from prokaryotic protein degradation to mammalian neuronal signaling.
• C-terminal interactions offer a potential indexing criterion for functional proteomics.