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Metazoans evolved by taking domains from soluble proteins to expand intercellular communication network
Hyun-Jun Nam1, Inhae Kim2, James U Bowie3
1School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.
Scientific Reports
|April 30, 2015
Summary
Membrane proteins evolved new complexities by incorporating domains from soluble proteins, driving the development of multicellular animals. This innovation facilitated cell adhesion, signaling, and immune defense in early metazoan life.
Area of Science:
- Evolutionary biology
- Molecular evolution
- Cell biology
Background:
- The evolution of multicellular animals from unicellular ancestors remains a central question in biology.
- Membrane proteins are hypothesized to be crucial for multicellularity due to their roles in cell-cell contact and communication.
Purpose of the Study:
- To investigate the evolutionary mechanisms behind the increased complexity of membrane proteins during the transition to multicellular animal life.
- To identify how membrane proteins acquired new functions essential for complex organisms.
Main Methods:
- Comparative genomic analysis of membrane proteins across different life forms.
- Domain analysis to identify novel incorporations in metazoan membrane proteins.
- Protein-protein interaction network analysis to assess functional impact.
Main Results:
- A significant mechanism for increased membrane protein complexity in metazoans was the incorporation of domains from soluble proteins.
- Metazoan membrane proteins with incorporated soluble domains are enriched in functions vital for multicellularity, including cell adhesion, signaling, immune defense, and development.
- These proteins exhibit increased protein-protein interaction network complexity and centrality, indicating a key role in cellular diversification.
Conclusions:
- The acquisition of soluble protein domains by membrane proteins was a critical evolutionary step enabling the development of multicellular animals.
- This process provided essential molecular machinery for the complex cellular interactions and functions characteristic of metazoans.
- Understanding this mechanism sheds light on the evolutionary trajectory towards higher life forms.
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