SIRT1, human ortholog of yeast SIR2 protein, deacetylates histones and several other transcription factors. Recently, SIRT1 has emerged as a drug target for treating age related diseases, type II diabetes, neurodegeneration, inflammation and cancer. Here, we have optimized production of functionally active wild type full-length SIRT1 protein and its N-terminal deleted mutants. In a comparative study, we found that the region containing 192-208 amino acids towards the N-terminus is critical for right conformational folding of the protein to retain its deacetylase activity. The EC(50) and IC(50) values obtained with standard modulators showed that the SRT(748) & SRT(556) can deacetylate substrate and are activated by resveratrol, whereas, deacetylase activity of all the other deletion mutants (SRT(540), SRT(532), SRT(507) and SRT(503)) was lost. We further report that the peptide substrate K(m) for SRT(748) (70+/-5.2 microM) was comparable to SRT(556) (93+/-5.4 microM). The K(m) for NAD(+) substrate was 176 & 274 microM for SRT(748) and SRT(556), respectively. Similar substrate affinity studies demonstrate that either of the protein (SRT(748) or SRT(556)) can be utilized for screening SIRT1 modulators. We have also examined critical regions in SIRT1 required for deacetylase activity as well as kinetic analyses of SIRT1 proteins.
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http://dx.doi.org/10.1016/j.bbrc.2009.11.130 | DOI Listing |
Cardiovasc Res
January 2025
Department of Pathophysiology, Shenzhen University Medical School, Shenzhen 518060, China.
Aims: Decrease in repolarizing K+ currents, particularly the fast component of transient outward K+ current (Ito,f), prolongs action potential duration (APD) and predisposes the heart to ventricular arrhythmia during cardiac hypertrophy. Histone deacetylases (HDACs) have been suggested to participate in the development of cardiac hypertrophy, and class I HDAC inhibition has been found to attenuate pathological remodeling. This study investigated the potential therapeutic effects of HDAC2 on ventricular arrhythmia in pressure overload-induced cardiac hypertrophy.
View Article and Find Full Text PDFPLoS One
January 2025
Division of Oral Physiology, Faculty of Dentistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
This study examined the effects of treadmill running (TR) regimens on craniofacial pain- and anxiety-like behaviors, as well as their effects on neural changes in specific brain regions of male mice subjected to repeated social defeat stress (SDS) for 10 days. Behavioral and immunohistochemical experiments were conducted to evaluate the impact of TR regimens on SDS-related those behaviors, as well as epigenetic and neural activity markers in the anterior cingulate cortex (ACC), insular cortex (IC), rostral ventromedial medulla (RVM), and cervical spinal dorsal horn (C2). Behavioral responses were quantified using multiple tests, while immunohistochemistry measured histone H3 acetylation, histone deacetylases (HDAC1, HDAC2), and neural activity markers (FosB and phosphorylated cAMP response element-binding protein (pCREB).
View Article and Find Full Text PDFInt Rev Cell Mol Biol
January 2025
Department of Biochemistry, CSIR-Central Food Technological Research Institute, Mysore, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India. Electronic address:
In preclinical studies, bioactive phytochemicals have shown enormous potential therapeutic efficacy against various human malignancies. These natural compounds have been shown to possess an inherent potential to alter the molecular signaling pathways and epigenetic modulatory activity involved in multiple physiological functions. Recently, epigenetic therapy has emerged as an important therapeutic modality due to the reversible nature of epigenetic alterations.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Basis Dis
January 2025
Department of Public Health Genomics, Centre for DNA Repair and Genome Stability (CDRGS), Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India. Electronic address:
Mammalian sirtuins are class III histone deacetylases involved in the regulation of multiple biological processes including senescence, DNA repair, apoptosis, proliferation, caloric restriction, and metabolism. Among the mammalian sirtuins, SIRT3, SIRT4, and SIRT5 are localized in the mitochondria and collectively termed the mitochondrial sirtuins. Mitochondrial sirtuins are NAD+-dependent deacetylases that play a central role in cellular metabolism and function as epigenetic regulators by performing post-translational modification of cellular proteins.
View Article and Find Full Text PDFNeoplasia
January 2025
Leipzig University, Medical Faculty, Rudolf-Boehm-Institute for Pharmacology and Toxicology, Clinical Pharmacology, Leipzig, Germany; Comprehensive Cancer Center Central Germany (CCCG), Leipzig and Jena. Electronic address:
Introduction: Histone deacetylase inhibitors (HDACi) have shown promising preclinical activity in gastric cancer cells; unfortunately, however, these could not be confirmed in clinical trials. This highlights the need for the identification of underlying reasons, which may also provide the basis for possible combination therapies. Here, we delineated the effects of HDACi on components of EGFR signalling in gastric cancer cells.
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