Deciphering function and mechanism of calcium-binding proteins from their evolutionary imprints

Area of Science:

• Computational biology
• Molecular evolution
• Biochemistry

Background:

• Calcium-binding proteins are crucial for ion metabolism and cellular signaling.
• Understanding their molecular basis requires evolutionary and structural analysis.

Purpose of the Study:

• To elucidate the molecular basis of calcium-binding protein function through evolutionary studies.
• To investigate the structural diversity and functional implications of major calcium-binding protein families.

Main Methods:

• Phylogenetic analysis for ortholog classification.
• Profile hidden Markov models (HMM) for identifying conserved functional sites.
• 3D structure analysis to visualize protein context.

Main Results:

• Major calcium-binding protein families (EF-hand, C2, ANX) show subfamily-specific HMM fingerprints linked to functional variations.
• Evolutionary analysis in sea lamprey documented gene duplication and creation events.
• Novel annexins from diverse organisms displayed unique molecular fingerprints and functional specificities.

Conclusions:

• Structural diversity in calcium-binding proteins influences protein conformation, interaction sites, and membrane binding.
• Evolutionary studies reveal unique annexin features across various taxa, from bacteria to humans.
• Receptor docking models suggest annexin-C2 domain interactions facilitate membrane translocation in signal transduction.