Decoding the ubiquitin language: Orchestrating transcription initiation and gene expression through chromatin remodelers and histones.

Eukaryotic transcription is a finely orchestrated process and it is controlled by transcription factors as well as epigenetic regulators. Transcription factors and epigenetic regulators undergo different types of posttranslational modifications including ubiquitination to control transcription process. Ubiquitination, traditionally associated with protein degradation, has emerged as a crucial contributor to the regulation of chromatin structure through ubiquitination of histone and chromatin remodelers. Ubiquitination introduces new layers of intricacy to the regulation of transcription initiation through controlling the equilibrium between euchromatin and heterochromatin states. Nucleosome, the fundamental units of chromatin, spacing in euchromatin and heterochromatin states are regulated by histone modification and chromatin remodeling complexes. Chromatin remodeling complexes actively sculpt the chromatin architecture and thereby influence the transcriptional states of genes. Therefore, understanding the dynamic behavior of nucleosome spacing is critical as it impacts various cellular functions through controlling gene expression profiles. In this comprehensive review, we discussed the intricate interplay between ubiquitination and transcription initiation, and illuminated the underlying molecular mechanisms that occur in a variety of biological contexts. This exploration sheds light on the complex regulatory networks that govern eukaryotic transcription, providing important insights into the fine orchestration of gene expression and chromatin dynamics.

A single step and rapid protein extraction protocol developed for cell lines and tissues: Compatible for gel based and gel free proteomic approaches.

Proteins are crucial research molecules in modern biology. Almost every biological research area needs protein-based assays to answer the research questions. The study of the total protein content of a biological sample known as Proteomics, is one of the highly rated qualitative and quantitative approach to address numerous biological problems including clinical research. The key step to successfully generate high quality proteomics data is the efficient extraction of proteins from biological samples. Although different methods are in use for protein extraction from a wide variety of samples, however, because of their prolonged protocol and multiple steps involved, final protein yield is sacrificed. Here, we have shown the development of a simple single step method for extraction of proteins from mammalian cell lines as well as tissue samples in an effective and reproducible manner. This method is based on lysis of samples directly in a modified lysis buffer without CHAPS (7 M Urea, 2 M Thiourea, and 10 mM Tris-Cl; pH 8.5) that is compatible with gel based and gel free approaches. This developed protocol is reliable and should be useful for a wide range of proteomic studies involving various biological samples.

Enhanced stability of microtubules contributes in the development of colchicine resistance in MCF-7 cells.

Understanding the mechanism of resistance to tubulin-targeted anticancer drugs is important for improved chemotherapy. In this work, a colchicine-resistant MCF-7 cell line (MCF-7Col30) was generated by the gradual increment of colchicine treatment and the MCF-7Col30 showed ∼8-fold resistance towards colchicine. MCF-7Col30 cells showed ∼2.5-fold resistance against microtubule depolymerizing agents, vinblastine, and nocodazole. In contrast, it displayed more sensitivity towards paclitaxel, a microtubule-polymerizing agent. MCF-7 and MCF-7Col30 cells showed similar sensitivity towards cisplatin. Further, the level of P-glycoprotein did not increase in MCF-7Col30 cells. MCF-7Col30 cells resisted the microtubule depolymerizing effects of colchicine. The time-lapse imaging of individual microtubules in live cells showed that the dynamics of microtubules in MCF-7Col30 cells was suppressed as compared to the parent MCF-7 cells. The levels of tubulin acetylation and glutamylation increased in MCF-7Col30 cells than the parent MCF-7 cells suggesting that microtubules are stabilized in MCF-7Col30 cells. Interestingly, the level of ßIII tubulin was increased by 2.3 folds whereas that of ßII and ßIV tubulin was decreased by 55 and 150%, respectively in MCF-7Col30 cells. The results suggested that the changes in the level of ß-tubulin isoforms and the post-translational modifications of microtubules altered the stability and dynamics of microtubules and contributed to the development of colchicine-resistance in MCF-7 cells.