Modulating protein function with low-complexity amino acid tags
Abstract
Synthetic biology has begun to reshape nearly all fields from energy production to personalized medicine. Advances in the engineering of gene circuits, as well as innovations in genome editing, have made it possible to introduce any designer gene or pathway into a microorganism. However, there is a continued need to develop newer and better strategies to regulate protein function in order to perform more complex and novel biological activities. Protein scientists continue to explore the fundamental properties of proteins and protein domains in the hope that we can create modules that facilitate or regulate novel protein function either in cells or cell-free systems. Until recently, most studies of protein structure and function have focused on how sequences fold into discrete, stable domains that carry out various function. Although abundant in proteins, regions of repetitive amino acid sequence have been overlooked in these functional studies. In recent years, these, and other low-complexity (LC) domains in proteins have sparked interest as they are associated with intrinsically disordered regions (IDRs), and have unique biophysical properties. For example, LC domains have been predicted to regulate dynamic protein associations including aggregation, phase separation, and association with membraneless organelles such as P-bodies or stress granules. More recently, many LC domains have been shown to have prion-like qualities, able to be passed from cell to cell. The coding regions of repetitive low-complexity (rLC) domains also exhibit high rates of genetic instability leading to population-level polymorphism. We and others have proposed that the genetic instability in rLC domains contributes not only to disease but also to rapid evolution in proteins and phenotypic variation between individuals. This has led to various models about how rLC regions, and repeat variation might contribute to the regulation of protein function. The emerging properties of IDRs, and rLC domains in particular, highlight their potential role in responding to environmental changes in cells, and interrogation of these mechanisms will lead to new advances in protein engineering and synthetic biology. A goal of synthetic biology is to understand the design of biological systems well enough to combine the building blocks in new ways to produce new/better outcomes. In the past few years our lab has focused on understanding the unique biology and potential of repetitive protein sequences to impart novel biology. This proposal builds upon our tools and experience with repetitive amino acid motifs and emerging roles for these sequences in dynamic protein regulation processes. In three technical objectives we intend to: define the roles that repeat sequence and length polymorphism play in tuning protein function, explore the emergent properties of less-studied rLC domains, and through model studies, test the potential for rLCs to regulate synthetic systems. This work is fundamental to the development of biology-inspired cell-based, and cell-free sensors, for a range of Army goals from battlefield preparedness to assessing the capacity of space environments to sustain human communities. Also critical to the work is the training and development of future scientists. Research in the lab is focused on using multidisciplinary approaches and training scientists to be able communicate with researchers from a variety of disciplines. This is critically important for the mission of the Army Futures Command (AFC) where there is great focus on working within cross-functional teams. By utilizing tools from genetics, engineering, synthetic biology, computational biology, materials science and chemistry Ð students in my lab learn the language of many disciplines which makes them better equipped to meet the needs of AFC in the future as well as the US workforce.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 28, 2019
- Source ID
- W911NF1910299
Entities
People
- Stephen M. Fuchs
Organizations
- Army Contracting Command
- Tufts University
- United States Army