Role of Post-Translational Protein Modification in Community-Scale Processes


Although biological processes are often modulated by the direct regulation of gene expression, post-translational modifications (PTM) of expressed proteins frequently play an equally important regulatory role. PTM occurs when protein function is altered by the addition of a phosphate, acetate, or other small molecule in response to a sensed environmental cue. These alterations create rippling signal cascades, often leading to pervasive changes in cellular metabolism and functional properties. PTM-based regulation has been extensively studied in individual organisms, but the role of this regulatory mechanism at the scale of complex communities remains poorly understood. In a new study, a collaborative team of researchers at the University of California, Berkeley, and Oak Ridge National Laboratory developed a novel technique that allows PTM analysis in proteins collected from an intact microbial community (i.e., the metaproteome) using high-resolution mass spectrometry coupled to high-performance computing. The investigators examined PTM in a model biofilm community found in a highly acidic environment and were able to link this regulatory mechanism to several community-scale phenotypes that could not be explained by observed changes in gene expression. Community-level attributes associated with PTM in this study included alterations in community structure, nutrient acquisition strategies, and resistance to viral invasion. This finding represents a considerable advance in the application of systems biology approaches to community-level analysis. The team now is working to scale up this technique to enable investigations of more complex communities and environments.


Li, Z., Y. Wang, Q. Yao, N. B. Justice, T.-H. Ahn, D. Xu, R. L. Hettich, J. F. Banfield, and C. Pan. 2014. “Diverse and Divergent Protein Post Translational Modifications in Two Growth Stages of a Natural Microbial Community,” Nature Communications 5, 4405. DOI: 10.1038/ncomms5405.