Expansion of DUB functionality generated by alternative isoforms - USP35, a case study.

Protein ubiquitylation is a dynamic post-translational modification that can be reversed by deubiquitylating enzymes (DUBs). It is unclear how the small number (∼100) of DUBs present in mammalian cells regulate the thousands of different ubiquitylation events. Here, we analysed annotated transcripts of human DUBs and found ∼300 ribosome-associated transcripts annotated as protein coding, which thus increases the total number of DUBs. By using USP35, a poorly studied DUB, as a case study, we provide evidence that alternative isoforms contribute to the functional expansion of DUBs. We show that there are two different USP35 isoforms that localise to different intracellular compartments and have distinct functions. Our results reveal that isoform 1 is an anti-apoptotic factor that inhibits staurosporine- and TNF-related apoptosis-inducing ligand (TRAIL; also known as TNFSF10)-induced apoptosis. In contrast, USP35 isoform 2 is an integral membrane protein of the endoplasmic reticulum (ER) that is also present at lipid droplets. Manipulations of isoform 2 levels cause rapid ER stress, likely through deregulation of lipid homeostasis, and lead to cell death. Our work highlights how alternative isoforms provide functional expansion of DUBs and sets directions for future research.This article has an associated First Person interview with the first author of the paper.

A critical overview of challenging roles of medicinal plants in improvement of wound healing technology.

PURPOSE: Chronic diseases often hinder the natural healing process, making wound infections a prevalent clinical concern. In severe cases, complications can arise, potentially leading to fatal outcomes. While allopathic treatments offer numerous options for wound repair and management, the enduring popularity of herbal medications may be attributed to their perceived minimal side effects. Hence, this review aims to investigate the potential of herbal remedies in efficiently treating wounds, presenting a promising alternative for consideration. METHODS: A literature search was done including research, reviews, systematic literature review, meta-analysis, and clinical trials considered. Search engines such as Pubmed, Google Scholar, and Scopus were used while retrieving data. Keywords like Wound healing 'Wound healing and herbal combinations', 'Herbal wound dressing', Nanotechnology and Wound dressing were used. RESULT: This review provides valuable insights into the role of natural products and technology-based formulations in the treatment of wound infections. It evaluates the use of herbal remedies as an effective approach. Various active principles from herbs, categorized as flavonoids, glycosides, saponins, and phenolic compounds, have shown effectiveness in promoting wound closure. A multitude of herbal remedies have demonstrated significant efficacy in wound management, offering an additional avenue for care. The review encompasses a total of 72 studies, involving 127 distinct herbs (excluding any common herbs shared between studies), primarily belonging to the families Asteraceae, Fabaceae, and Apiaceae. In research, rat models were predominantly utilized to assess wound healing activities. Furthermore, advancements in herbal-based formulations using nanotechnology-based wound dressing materials, such as nanofibers, nanoemulsions, nanofiber mats, polymeric fibers, and hydrogel-based microneedles, are underway. These innovations aim to enhance targeted drug delivery and expedite recovery. Several clinical-based experimental studies have already been documented, evaluating the efficacy of various natural products for wound care and management. This signifies a promising direction in the field of wound treatment. CONCLUSION: In recent years, scientists have increasingly utilized evidence-based medicine and advanced scientific techniques to validate the efficacy of herbal medicines and delve into the underlying mechanisms of their actions. However, there remains a critical need for further research to thoroughly understand how isolated chemicals extracted from herbs contribute to the healing process of intricate wounds, which may have life-threatening consequences. This ongoing research endeavor holds great promise in not only advancing our understanding but also in the development of innovative formulations that expedite the recovery process.

Potential of Flavonoids as Promising Phytotherapeutic Agents to Combat Multidrug-Resistant Infections.

BACKGROUND: Considering the limited number of current effective treatments, Multidrug- Resistant (MDR) illnesses have grown to be a serious concern to public health. It has become necessary to look for new antimicrobial drugs because of the emergence of resistance to numerous kinds of antibiotics. The use of flavonoids is one phytotherapeutic strategy that has been researched as a potential remedy for this issue. Secondary plant compounds called flavonoids have been found to have an antibacterial effect against resistant microorganisms. OBJECTIVE: This review seeks to give readers a glimpse into contemporary studies on flavonoids' potential to fight MDR infections. METHODS: A systematic search was conducted on electronic databases (PubMed, Scopus, and Google Scholar) using relevant keywords such as flavonoids, MDR infections, antimicrobial activity, and resistance microbes. Studies that investigated the antimicrobial activity of flavonoids against resistant microbes were included in this review. RESULTS: Most research found that flavonoids have antibacterial efficacy against resistant microorganisms, and some also showed that they have synergistic benefits with traditional antibiotics. The flavonoids quercetin, kaempferol, apigenin, and luteolin were the most often investigated ones. According to research, flavonoids affect microbial gene expression, inhibit microbial enzymes, and disrupt the integrity of microbial cell membranes. Additionally, a few studies have noted the flavonoids' low toxicity and safety. CONCLUSION: For the treatment of infections that are resistant to many drugs, flavonoids constitute a promising class of phytotherapeutic agents. To develop flavonoid-based treatment methods for treating MDR illnesses and assess the potential of flavonoids as adjuvants to conventional antimicrobial drugs, more study is required.

The alr-groEL1 operon in Mycobacterium tuberculosis: an interplay of multiple regulatory elements.

Threonylcarbamoyladenosine is a universally conserved essential modification of tRNA that ensures translational fidelity in cellular milieu. TsaD, TsaB and TsaE are identified as tRNA-A37-threonylcarbamoyl (t6A)-transferase enzymes that have been reconstituted in vitro, in few bacteria recently. However, transcriptional organization and regulation of these genes are not known in any of these organisms. This study describes the intricate architecture of a complex multicistronic alr-groEL1 operon, harboring essential genes, namely tsaD, tsaB, tsaE, groES, groEL1, and alr (required for cell wall synthesis), and rimI encoding an N-α- acetyltransferase in Mycobacterium tuberculosis. Using northern blotting, RT-PCR and in vivo fluorescence assays, genes alr to groEL1 were found to constitute an ~6.3 kb heptacistronic operon with multiple internal promoters and an I-shaped intrinsic hairpin-like cis-regulatory element. A strong promoter PtsaD within the coding sequence of rimI gene is identified in M. tuberculosis, in addition. The study further proposes an amendment in the known bicistronic groESL1 operon annotation by providing evidence that groESL1 is co-transcribed as sub-operon of alr-groEL1 operon. The architecture of alr-groEL1 operon, conservation of the genetic context and a mosaic transcriptional profile displayed under various stress conditions convincingly suggest the involvement of this operon in stress adaptation in M. tuberculosis.

Biochemical evidence for relaxed substrate specificity of Nα-acetyltransferase (Rv3420c/rimI) of Mycobacterium tuberculosis.

Nα-acetylation is a naturally occurring irreversible modification of N-termini of proteins catalyzed by Nα-acetyltransferases (NATs). Although present in all three domains of life, it is little understood in bacteria. The functional grouping of NATs into six types NatA - NatF, in eukaryotes is based on subunit requirements and stringent substrate specificities. Bacterial orthologs are phylogenetically divergent from eukaryotic NATs, and only a couple of them are characterized biochemically. Accordingly, not much is known about their substrate specificities. Rv3420c of Mycobacterium tuberculosis is a NAT ortholog coding for RimI(Mtb). Using in vitro peptide-based enzyme assays and mass-spectrometry methods, we provide evidence that RimI(Mtb) is a protein Nα-acetyltransferase of relaxed substrate specificity mimicking substrate specificities of eukaryotic NatA, NatC and most competently that of NatE. Also, hitherto unknown acetylation of residues namely, Asp, Glu, Tyr and Leu by a bacterial NAT (RimI(Mtb)) is elucidated, in vitro. Based on in vivo acetylation status, in vitro assay results and genetic context, a plausible cellular substrate for RimI(Mtb) is proposed.