scholarly journals Genuine Selective Caspase-2 Inhibition with new Irreversible Small Peptidomimetics

2021 ◽  
Author(s):  
Elodie Bosc ◽  
Julie Anastasie ◽  
Feryel Soualmia ◽  
Pascale Coric ◽  
Ju Youn Kim ◽  
...  
Keyword(s):  
Stress Responses ◽  
Hippocampal Neurons ◽  
Active Sites ◽  
Spatial Configuration ◽  
Regulatory Element ◽  
Inactivation Rate ◽  
Promising Therapeutic Target ◽  
Element Binding Protein ◽  
Caspase Family ◽  
Caspase 2

Caspase-2 (Casp2) is a promising therapeutic target in several human diseases including nonalcoholic steatohepatitis (NASH) and Alzheimer's disease (AD). However, the design of active-site-directed inhibitor selective to individual caspase family members is challenging because caspases have extremely similar active sites. Here we present new peptidomimetics derived from the VDVAD pentapeptide structure, harboring non-natural modifications at the P2 position and an irreversible warhead. Enzyme kinetics shows that these new compounds, such as LJ2 or its specific isomer LJ2a, and LJ3a, strongly and irreversibly inhibit Casp2 with genuine selectivity. According to Casp2 role in cellular stress responses, LJ2 inhibits cell death induced by microtubule destabilization or hydroxamic acid-based deacetylase inhibition. The most potent peptidomimetic, LJ2a, inhibits human Casp2 with a remarkably high inactivation rate (k3/Ki ~ 5 500 000 M-1s-1) and the most selective inhibitor, LJ3a, has a near to 1000 times higher inactivation rate on Casp2 as compared to Casp3. Structural analysis of LJ3a shows that spatial configuration of C[alpha]; at the P2 position determines inhibitor efficacy. In transfected human cell lines overexpressing site-1 protease (S1P), sterol regulatory element-binding protein 2 (SREBP2) and Casp2, LJ2a and LJ3a fully inhibit SREBP2 activation, suggesting a potential to prevent NASH development. Furthermore, in primary hippocampal neurons treated with [beta]-amyloid oligomers, submicromolar concentrations of LJ2a and of LJ3a prevent synapse loss, indicating a potential for further investigations in AD treatment.

scholarly journals Caspase-2, a Novel Lipid Sensor under the Control of Sterol Regulatory Element Binding Protein 2

2005 ◽  
Vol 25 (21) ◽  
pp. 9621-9631 ◽  
Author(s):  
E. Logette ◽  
C. Le Jossic-Corcos ◽  
D. Masson ◽  
S. Solier ◽  
A. Sequeira-Legrand ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Apoptotic Cell ◽  
Regulatory Element ◽  
Acid Synthesis ◽  
Lipid Lowering ◽  
Proteolytic Activation ◽  
Element Binding Protein ◽  
Sterol Regulatory Element ◽  
Caspase 2 ◽  
Interfering Rna

ABSTRACT Caspases play important roles in apoptotic cell death and in some other functions, such as cytokine maturation, inflammation, or differentiation. We show here that the 5′-flanking region of the human CASP-2 gene contains three functional response elements for sterol regulatory element binding proteins (SREBPs), proteins that mediate the transcriptional activation of genes involved in cholesterol, triacylglycerol, and fatty acid synthesis. Exposure of several human cell lines to statins, lipid-lowering drugs that drive SREBP proteolytic activation, induced the CASP-2 gene to an extent similar to that for known targets of SREBP proteins. Adenoviral vector-mediated transfer of active SREBP-2 also induced expression of the CASP-2 gene and the caspase-2 protein and increased the cholesterol and triacylglycerol cellular content. These rises in lipids were strongly impaired following small interfering RNA-mediated silencing of the CASP-2 gene. Taken together, our results identify the human CASP-2 gene as a member of the SREBP-responsive gene battery that senses lipid levels in cells and raise the possibility that caspase-2 participates in the control of cholesterol and triacylglycerol levels.

scholarly journals The membrane anchor of the transcriptional activator SREBP is characterized by intrinsic conformational flexibility

2015 ◽  
Vol 112 (40) ◽  
pp. 12390-12395 ◽  
Author(s):  
Rasmus Linser ◽  
Nicola Salvi ◽  
Rodolfo Briones ◽  
Petra Rovó ◽  
Bert L. de Groot ◽  
...  
Keyword(s):  
Stress Responses ◽  
Chemical Shifts ◽  
Transmembrane Protein ◽  
Regulatory Element ◽  
Conformational Flexibility ◽  
Therapeutic Interventions ◽  
Solvent Exposure ◽  
Element Binding Protein ◽  
Lipid Environment ◽  
Dynamics Simulations

Regulated intramembrane proteolysis (RIP) is a conserved mechanism crucial for numerous cellular processes, including signaling, transcriptional regulation, axon guidance, cell adhesion, cellular stress responses, and transmembrane protein fragment degradation. Importantly, it is relevant in various diseases including Alzheimer’s disease, cardiovascular diseases, and cancers. Even though a number of structures of different intramembrane proteases have been solved recently, fundamental questions concerning mechanistic underpinnings of RIP and therapeutic interventions remain. In particular, this includes substrate recognition, what properties render a given substrate amenable for RIP, and how the lipid environment affects the substrate cleavage. Members of the sterol regulatory element-binding protein (SREBP) family of transcription factors are critical regulators of genes involved in cholesterol/lipid homeostasis. After site-1 protease cleavage of the inactive SREBP transmembrane precursor protein, RIP of the anchor intermediate by site-2 protease generates the mature transcription factor. In this work, we have investigated the labile anchor intermediate of SREBP-1 using NMR spectroscopy. Surprisingly, NMR chemical shifts, site-resolved solvent exposure, and relaxation studies show that the cleavage site of the lipid-signaling protein intermediate bears rigid α-helical topology. An evolutionary conserved motif, by contrast, interrupts the secondary structure ∼9–10 residues C-terminal of the scissile bond and acts as an inducer of conformational flexibility within the carboxyl-terminal transmembrane region. These results are consistent with molecular dynamics simulations. Topology, stability, and site-resolved dynamics data suggest that the cleavage of the α-helical substrate in the case of RIP may be associated with a hinge motion triggered by the molecular environment.

Protein in culture and endogenous lipid interact with embryonic stages in vitro to alter calf birthweight after embryo vitrification and warming

2017 ◽  
Vol 29 (10) ◽  
pp. 1932 ◽  
Author(s):  
E. Gómez ◽  
S. Carrocera ◽  
S. Uzbekova ◽  
D. Martín ◽  
A. Murillo ◽  
...  
Keyword(s):  
Stress Responses ◽  
Regulatory Element ◽  
Pregnancy Rates ◽  
Hormone Sensitive Lipase ◽  
Expression Of Genes ◽  
Element Binding Protein ◽  
Sterol Regulatory Element ◽  
Hormone Sensitive

Short-term protein removal in vitro improves long-term blastocyst competence to survive vitrification. We investigated the mechanisms and effects underlying protein removal. Day-6 morulae and early blastocysts were cultured individually with and without protein for 24 h. Development and lipid content were analysed in expanded blastocysts derived from morulae (M-XB) and from early blastocysts (EB-XB). Expression of genes involved in lipid metabolism, stress responses and apoptosis was analysed in fresh and vitrified–warmed M-XB produced with and without protein. Pregnancy rates, birth rates and birthweight (BW) were recorded after transfer of embryos. Day-7 EB-XB production rates (with, 66.9 ± 6.2 and without, 68.8 ± 6.0 protein) were higher than M-XB rates (with, 21.4 ± 4.6 and without, 9.4 ± 4.6 protein; P < 0.005). EB-XB showed fewer lipids than M-XB (P = 0.03). In fresh M-XB, expression of sterol regulatory element binding protein (SREBP1) was lower with (4.1 ± 2.2) than without (13.6 ± 2.2) protein, contrary to results obtained for Patatin-like phospholipase domain containing 2, Hormone-sensitive lipase and Bcl-2–associated X protein (P < 0.05). Protein did not affect pregnancy rates and birth phenotypes (P > 0.05). However, BW was higher (P < 0.01) in calves born from vitrified M-XB (48.6 ± 3.4 kg) than from EB-XB (39.8 ± 2.9 kg). Such effects were more pronounced in females (P < 0.001). Calves from fresh embryos did not show BW differences. These results indicate that embryonic kinetics and vitrification impact birth phenotypes, at least in females. Alterations might involve exogenous protein and mobilisation of lipid stocks.

scholarly journals Hairpin Orientation of Sterol Regulatory Element-binding Protein-2 in Cell Membranes as Determined by Protease Protection

1995 ◽  
Vol 270 (49) ◽  
pp. 29422-29427 ◽  
Author(s):  
Xianxin Hua ◽  
Juro Sakai ◽  
Ho Y. K. ◽  
Joseph L. Goldstein ◽  
Michael S. Brown
Keyword(s):  
Cell Membranes ◽  
Binding Protein ◽  
Regulatory Element ◽  
Element Binding Protein ◽  
Sterol Regulatory Element

scholarly journals Sterol Regulatory Element Binding Protein 1a Regulates Hepatic Fatty Acid Partitioning by Activating Acetyl Coenzyme A Carboxylase 2

2009 ◽  
Vol 29 (17) ◽  
pp. 4864-4872 ◽  
Author(s):  
Seung-Soon Im ◽  
Linda E. Hammond ◽  
Leyla Yousef ◽  
Cherryl Nugas-Selby ◽  
Dong-Ju Shin ◽  
...  
Keyword(s):  
Insertional Mutagenesis ◽  
Coenzyme A ◽  
Binding Protein ◽  
Regulatory Element ◽  
Fatty Acyl ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Element Binding Protein ◽  
Sterol Regulatory Element ◽  
Microarray Expression

ABSTRACT We generated a line of mice in which sterol regulatory element binding protein 1a (SREBP-1a) was specifically inactivated by insertional mutagenesis. Homozygous mutant mice were completely viable despite expressing SREBP-1a mRNA below 5% of normal, and there were minimal effects on expression of either SREBP-1c or -2. Microarray expression studies in liver, where SREBP-1a mRNA is 1/10 the level of the highly similar SREBP-1c, demonstrated that only a few genes were affected. The only downregulated genes directly linked to lipid metabolism were Srebf1 (which encodes SREBP-1) and Acacb (which encodes acetyl coenzyme A [acetyl-CoA] carboxylase 2 [ACC2], a critical regulator of fatty acyl-CoA partitioning between cytosol and mitochondria). ACC2 regulation is particularly important during food restriction. Similar to Acacb knockout mice, SREBP-1a-deficient mice have lower hepatic triglycerides and higher serum ketones during fasting than wild-type mice. SREBP-1a and -1c have identical DNA binding and dimerization domains; thus, the failure of the more abundant SREBP-1c to substitute for activating hepatic ACC2 must relate to more efficient recruitment of transcriptional coactivators to the more potent SREBP-1a activation domain. Our chromatin immunoprecipitation results support this hypothesis.

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