Priyanka Barman, Pritam Chakraborty, Shalini Guha, Amala Kaja, Rhea Bhaumik, Sukesh R Bhaumik
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引用次数: 0
Abstract
An evolutionarily conserved heterodimeric FACT (Facilitates chromatin transcription) regulates transcription, DNA repair, replication and other cellular processes via its interactions with other proteins. FACT is recently found to be regulated via ubiquitylation and 26S proteasomal degradation, alteration of which is associated with aberrant transcription and genome integrity. However, there has not been a systematic study to analyze FACT interactions proteome-wide in the presence and absence of its UPS (Ubiquitin-proteasome system) regulation, which could reveal new FACT interactors with mechanistic and functional implications. Here, we have adopted a proteome-wide approach via TAP (Tandem affinity purification)-mediated pull-down of FACT and its interactors from the soluble and insoluble cellular fractions followed by MS (Mass-spectrometry) analysis. We find distinct interactors of FACT in the soluble and insoluble fractions in addition to a common set in both. While a set of all these interactors overlaps with previously known FACT partners, many are new, which are involved in different cellular processes such as transcription, DNA repair and chromatin regulation. Further, an intrinsically disordered ubiquitin ligase, San1, that ubiquitylates the Spt16 component of FACT for proteasomal degradation to regulate chromatin, transcription and genome integrity is found to influence the interactions of FACT with a set of proteins including epigenetic, transcription and DNA repair factors. Collectively, our results unveil proteome-wide FACT interactions and regulation by a ubiquitin ligase, hence shedding much light on FACT networks with functional and mechanistic implications.
期刊介绍:
BBA Gene Regulatory Mechanisms includes reports that describe novel insights into mechanisms of transcriptional, post-transcriptional and translational gene regulation. Special emphasis is placed on papers that identify epigenetic mechanisms of gene regulation, including chromatin, modification, and remodeling. This section also encompasses mechanistic studies of regulatory proteins and protein complexes; regulatory or mechanistic aspects of RNA processing; regulation of expression by small RNAs; genomic analysis of gene expression patterns; and modeling of gene regulatory pathways. Papers describing gene promoters, enhancers, silencers or other regulatory DNA regions must incorporate significant functions studies.