The Effect of Dysfunctional Ubiquitin Enzymes in the Pathogenesis of Most Common Diseases

Ubiquitination is a multi-step enzymatic process that involves the marking of a substrate protein by bonding a ubiquitin and protein for proteolytic degradation mainly via the ubiquitin–proteasome system (UPS). The process is regulated by three main types of enzymes, namely ubiquitin-activating enzymes (E1), ubiquitin-conjugating enzymes (E2), and ubiquitin ligases (E3). Under physiological conditions, ubiquitination is highly reversible reaction, and deubiquitinases or deubiquitinating enzymes (DUBs) can reverse the effect of E3 ligases by the removal of ubiquitin from substrate proteins, thus maintaining the protein quality control and homeostasis in the cell. The dysfunction or dysregulation of these multi-step reactions is closely related to pathogenic conditions; therefore, understanding the role of ubiquitination in diseases is highly valuable for therapeutic approaches. In this review, we first provide an overview of the molecular mechanism of ubiquitination and UPS; then, we attempt to summarize the most common diseases affecting the dysfunction or dysregulation of these mechanisms

Quantum tunneling time delay investigation of K+ ion in human telomeric G-quadruplex systems

© 2023, The Author(s), under exclusive licence to Society for Biological Inorganic Chemistry (SBIC).Guanine-rich quadruplex DNA (G-quadruplex) is of interest both in cell biology and nanotechnology. Its biological functions necessitate a G-quadruplex to be stabilized against escape of the monovalent metal cations. The potassium ion (K+) is particularly important as it experiences a potential energy barrier while it enters and exits the G-quadruplex systems which are normally found in human telomere. In the present work, we analyzed the time it takes for the K+ cations to get in and out of the G-quadruplex. Our time estimate is based on entropic tunneling time—a time formula which gave biologically relevant results for DNA point mutation by proton tunneling. The potential energy barrier experienced by K+ ions is determined from a quantum mechanical simulation study, Schrodinger equation is solved using MATLAB, and the computed eigenfunctions and eigenenergies are used in the entropic tunneling time formula to compute the time delay and charge accumulation rate during the tunneling of K+ in G-quadruplex. The computations have shown that ion tunneling takes picosecond times. In addition, average K+ accumulation rate is found to be in the picoampere range. Our results show that time delay during the K+ ion tunneling is in the ballpark of the conformational transition times in biological systems, and it could be an important parameter for understanding its biological role in human DNA as well as for the possible applications in biotechnology. To our knowledge, for the first time in the literature, time delay during the ion tunneling from and into G-quadruplexes is computed. Graphical abstract: [Figure not available: see fulltext.

Clinical Correlates of Ambulatory Blood Pressure Phenotypes at a Tertiary Care Hospital in Turkey

Background/Aims: Hypertension and its complications are major public health issues worldwide due to their association with high cardiovascular morbidity and mortality. Despite significant progress in health, the prevalence of hypertension is increasing. Ambulatory blood pressure monitoring (ABPM) is becoming increasingly important for the management of hypertension. In this study, we aimed to investigate the clinical and laboratory correlates of ambulatory blood pressure (ABP) phenotypes at a tertiary care hospital in Turkey. Methods: The characteristics of 1053 patients were retrospectively obtained from the hospital database. Hypertension was defined as patients with office blood pressure (BP) ≥140/90 mmHg and/or previously diagnosed hypertension and/or the use of antihypertensive medication. According to the office BP and ABPM results patients were identified namely: (1) sustained normotensive (SNT) patients (both office BP and ABPM were normal), (2) sustained hypertensive (SHT) patients (both office BP and ABPM were high), (3) masked hypertensive (MHT) patients (office BP were normal, but ABPM were high), (4) white coat hypertensive (WCHT) patients (office BP were above limits, but ABPM were normal). Results: A total of 1053 patients were included to the study (female/male: 608/445 and mean age 55 ± 15 years). The mean age of patients with hypertension was significantly higher than without hypertension (p< 0.0001). Hypertension was more frequent in females (p=0.009). The rates of history of diabetes mellitus (DM), hyperlipidemia (HL), and chronic kidney disease (CKD) were higher in patients with hypertension (p< 0.0001). Among patients with hypertension (n=853, 81%), ABPM results showed that 388 (45%) of patients had SHT, 92 (11%) had MHT, and 144 (17%) had WCHT, whereas 229 (27%) had SNT. Patients with MHT were significantly older than patients with SNT (p=0.025). The prevalence of SHT was higher in men than in women, whereas the prevalence of WCHT was higher in women than in men (p< 0.0001). There was no significant difference between 4 groups with regard to body mass index (p=0.142), a history of DM (p=0.189) and smoking status (self-reported) (p=0.306). Patients with SHT had the highest prevalence of history of hypertension, HL and CKD (p< 0.0001). Among patients without hypertension, 26 (13%) of patients had MHT and none of those patients was on antihypertensive treatment. Conclusion: Potential usages of ABPM in Turkey may include screening of high risk individuals who have traditional cardiovascular risk factors. It also provides clinicians valuable information on abnormal ABP phenotypes. Future studies are needed to clarify the risk factors of different ABP phenotypes and to evaluate the role of ABPM on detection and control of hypertension

Impact of Personality Traits, Anxiety, Depression and Hopelessness Levels on Quality of Life in the Patients with Breast Cancer

Objective: The aim of this study was to investigate the impacts of personality traits, anxiety, depression and hopelessness levels on quality of life in the patients with breast cancer