Current Protein and Peptide Science - Volume 23, Issue 3, 2022

One salient hallmark of neurodegeneration is the accumulation of toxic protein aggregates in neuronal cells. This proteotoxicity culminates in the deterioration of neuronal function. In AD and related tauopathies, the microtubule-associated protein tau becomes hyperphosphorylated. Hyperphosphorylated tau forms neurofibrillary tangles (NFTs) within neurons, which constitute a unique feature of tauopathies, including AD. A recent study has exploited a novel molecular strategy to counteract hyperphosphorylated tau and enhance its degradation. Analogous to the PROTAC methodology, a novel dephosphorylation targeting chimera (DEPTAC) was designed to promote the molecular interaction between tau and phosphatase, which, in turn, augments its degradation. Herein, we briefly discuss this novel finding and its potential therapeutic implications.

Gasdermins are novel pore forming proteins that comprise Gasdermin A, Gasdermin B, Gasdermin C, Gasdermin D, Gasdermin E and Pejvakin (DFNB59). Recently, pyroptosis has been redefined as "Gasdermin mediated necrosis", as gasdermins are key regulators of apoptosis, necrosis, and pyroptosis. The discovery of the gasdermin family has broadened the field of pyroptosis studies. Studies have correlated gasdermins with several diseases. This review summarizes the physiological roles and signal transduction of gasdermins. It further highlights the role of gasdermins in pathological conditions like autoimmune disease, kidney diseases, and central nervous system diseases.

Background: Addictions are a group of chronic and recurrent diseases of the brain characterized by a pathological search for reward or relief through the use of a substance or other action. This situation implies an inability to control behavior, difficulty in permanent abstinence, a compelling desire to consume, decreased recognition of significant problems caused by behavior and interpersonal relationships, and a dysfunctional emotional response. The result is a decrease in the quality of life of the affected person, generating problems in their work, academic activities, social relationships, or family or partner relationships. Unfortunately, there are not enough pharmacotherapeutic solutions to treat addictions due to the complexity of their physiopathology and signaling pathways. Therefore, it is an imperative search for new pharmacological alternatives which may be used for this purpose. Purpose of Review: This review summarizes the main recent findings of the potential therapeutic effects of different cannabinoids on treating several addictions, including alcohol, opioids, methamphetamine, cocaine, and nicotine use disorders. Highlights Standpoints: It has been demonstrated that many phyto, synthetic, and endogenous cannabinoids may act as therapeutic molecules in this psychiatric pathology through their action on multiple cannabinoid receptors. To highlight, cannabinoid receptors, types 1 and 2 (CB1 and CB2) have a crucial role in modulating the anti-addictive properties of these compounds.

Cancer is fundamentally a disease of perturbed genes. Although many mutations can be marked in the genome of cancer or a transformed cell, the initiation and progression are driven by only a few mutational events, viz., driver mutations that progressively govern and execute the functional impacts. The driver mutations are thus believed to dictate and dysregulate the subsequent cellular proliferative function/decisions, thereby producing a cancerous state. Therefore, identifying the driver events from the genomic alterations in a patient’s cancer cell gained enormous attention recently for designing better targeting therapies and paving the way for precision cancer medicine. With rolling advancements in high-throughput omic technologies, analysis of genetic variations and gene expression profiles for cancer patients has become a routine clinical practice. However, it is anticipated that protein structural alterations resulting from such driver mutations can provide more direct and clinically relevant evidence of disease states than genetic signatures alone. This review comprehensively discusses various aspects and approaches that have been developed for the prediction of cancer drivers using genetic signatures and protein structures and their potential application in developing precision cancer therapies.

Current coronavirus disease (COVID-19) is regarded as a primary respiratory and vascular disease leading to acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and endothelial dysfunction (ED) in severe cases. The causative virus of COVID-19 is SARS-CoV-2, which binds angiotensin-converting enzyme 2 (ACE2) for its entry. It has been shown that ED is linked to various COVID-19 complications since endothelial cells are regarded as the chief barrier against SARS-CoV- 2 invasion. SARS-CoV-2-indued ED leads to endotheliitis and thrombosis due to endothelial nitric oxide (NO) inhibition with subsequent vasoconstriction and tissue hypoxia. Loss of vasodilator NO and anti-thrombin factor from endothelial SARS-CoV-2 infection contribute to the progression of vascular dysfunction and coagulopathy. Therefore, NO restoration improves pulmonary function and hinders viral replication during respiratory viral infections, including COVID-19. L-arginine is a semiessential amino acid that has antiviral and immunomodulatory effects as well as improves the biosynthesis of NO in endothelial cells. L-arginine may reduce the risk of ALI through inhibition of generation of peroxynitrite and suppression of the release of proinflammatory cytokines from alveolar macrophages. Of interest, restoration of NO by L-arginine may attenuate SARS-CoV-2 infection through different mechanisms, including reduction binding of SARS-CoV-2 to ACE2, inhibition of transmembrane protease serine-type 2 (TMPRSS2), critical for the activation of SARS-CoV-2 spike protein and cellular entry, inhibition proliferation and replication of SARS-CoV-2, and prevention of SARS-CoV-2-induced coagulopathy. In conclusion, through antiviral and immunomodulatory effects, L-arginine and released NO have mutual and interrelated actions against SARS-CoV-2 infection.

ATP-binding cassette subfamily A member 1 (ABCA1) protein plays an essential role in a variety of events, such as cholesterol and phospholipid efflux, nascent high-density lipoprotein (HDL) biosynthesis, phospholipid translocation. Thus, there has been much research activity aimed at understanding the molecular mechanisms of regulating ABCA1 expression. In this review, we first discuss ABCA1 structure, tissue distribution, cellular localization, and trafficking, as well as its function. Furthermore, current understanding of the molecular mechanisms involved in the regulation of ABCA1 expression is summarized. ABCA1 transcriptional regulation is mediated by a very complicated system, including nuclear receptor systems, factors binding to other sites in the ABCA1 promoter, cytokines, hormones, growth factors, lipid metabolites, enzymes, and other messengers/factors/pathways. In addition, ABCA1 posttranscriptional regulation is mediated by microRNA, long noncoding RNA, RNA-binding proteins, proteases, fatty acids, PDZ proteins, signaling proteins, and other factors. Compared to the transcriptional regulation of ABCA1, which is well established, the post-transcriptional regulation of ABCA1 expression is poorly understood.

Background: Clostridiodes (or Clostridium) difficile is a spore-forming, Gram-positive anaerobic bacterium that may cause symptoms ranging from diarrhea to pseudomembranous colitis. During the C. difficile infection (CDI), the two primary bacterial toxins, toxin A (TcdA) or toxin B (TcdB), disrupt host cell function mainly through the inactivation of small GTPases that regulate the actin cytoskeleton. Both toxins have complex structural organization containing several functional domains. Methods: Analytical bioinformatics tools are used to compare the extent of disorder within TcdA and TcdB proteins, and to see if the existence of structural disorder can be used to explain the difference in the functionality of these toxins. Results: This paper’s aim is to offer an overall review of the structural and functional differences between TcdA and TcdB. Conclusion: Results of our multifactorial bioinformatics analysis revealed that intrinsic disorder may play a role in the multifunctionality of C. difficile major toxins TcdA and TcdB, suggesting that intrinsic disorder may be related to their pathogenic mechanisms.