Diversity and evolution of membrane intrinsic proteins

Area of Science:

• Molecular Biology
• Evolutionary Biology
• Biochemistry

Background:

• Membrane intrinsic proteins (MIPs) are crucial for cellular water transport.
• The MIP family is ancient, diverse, and found across many organisms.
• Understanding MIP evolution is key to comprehending fundamental biological processes.

Purpose of the Study:

• To provide an updated and comprehensive phylogeny of MIPs.
• To investigate the evolutionary history and diversification of MIPs across diverse life forms.
• To analyze conserved protein positions and functional diversification within the MIP family.

Main Methods:

• Phylogenetic analysis of over 1700 MIP sequences.
• Comparative genomics of MIPs from unicellular eukaryotes, fungi, algae, mosses, and invertebrates.
• Analysis of conserved residues and functional diversification in human and Arabidopsis MIPs.

Main Results:

• The phylogeny supports deep orthology of X intrinsic proteins (XIPs) from unicellular eukaryotes to plants.
• Small intrinsic proteins (SIPs) originated in the common ancestor of all plants.
• Aquaglyceroporins (GLPs) expanded in Oomycetes and were lost in vascular plants and certain insects.
• Recurrent independent expansions diversified MIP structures and functions in eukaryotes.

Conclusions:

• MIP evolution is more complex than previously thought, with significant diversification in eukaryotes.
• The study clarifies the evolutionary origins and expansion patterns of key MIP subfamilies.
• Conserved regions and functional aspects of MIPs are understood within an evolutionary framework.