If DNA is the blueprint of life, proteins are the building blocks. Thus understanding the molecular basis of life requires a deep knowledge of proteins that make up all organisms. A theory of proteins allows one to interpret a genome, and thus holds great promise for human health. The biochemical studies pioneered by Anfinsen in the 1960s and the development of powerful methods (e.g. crystallography) established the sequence-structure-function paradigm. With the availability of completely sequenced genomes, it has become clear that a large fraction of any eukaryotic genome (>40%) encodes protein segments that do not autonomously fold into a defined tertiary structure (although they may contain secondary structural elements) and thus do not directly follow Anfinsen’s postulate. These regions are commonly referred to as intrinsically disordered regions (IDRs). IDRs are enriched in critical functions such as transcription and signaling, and have been linked with numerous diseases including neurodegeneration and cancer. Despite their importance and In contrast to structured regions, the molecular principles behind the sequence-function relationship of IDRs remain poorly understood. Therefore it is critical to understand what makes certain disordered regions functional and why mutations in certain IDRs lead to disease.
The overall objectives of this proposal is to identify and characterize functional IDRs in cells, and to discover genes involved in their regulation using yeast as a cellular model. We proposed to develop and apply a targeted, high-throughput, multiplexed approach that we call IdrSeq (for Intrinsically disordered region Sequencing). This has been achieved now and published in an open access journal (Ravarani et al, MSB 2018). Specifically, using IdrSeq, we aim to discover and characterize IDRs that can
(Aim 1) function in transcriptional activation, and discover genes that modulate transcriptional activity
(Aim 2) influence protein stability, and discover genes involved in regulating half-life and
(Aim 3) form higher-order assemblies and discover genes that regulate assembly formation
The unique feature of this proposal is its integrative vision of synthetic & systems biology, (un)structural biology, cell biology, genetics, experiments and computation to establish a discovery platform to study IDRs in a cellular context. Since IdrSeq is modular and scalable, it can be readily extended to investigate a broad range of IDR functions, and adapted to other organisms. Elucidating the principles of sequence-function-gene relationship of IDRs holds enormous potential for synthetic biology. The discovery of genes that regulate IDR function has direct implications for human health by revealing novel therapeutic targets.
