Histone demethylase KDM6B regulates human podocyte differentiation in vitro
In this study, we first examined the expression pattern of histone demethylase KDM6B at different times of cultured human podocytes in vitro. We found that the expression of KDM6B and podocyte differentiation markers WT1 and Nephrin are increased in the podocyte differentiation process. In cultured podocytes, KDM6B knockdown with siRNA impaired podocyte differentiation and led to expression down-regulation of WT1 and Nephrin. The treatment of podocytes with GSK-J4, a specific KDM6B inhibitor, can also obtain similar results. Overexpression of WT1 can rescue differentiated phenotype impaired by disruption of KDM6B. ChIP (ch...
Source: Biochemical Journal - June 25, 2019 Category: Biochemistry Authors: Guo, Y., Xiong, Z., Guo, X. Tags: Research Articles Source Type: research
AMP-activated protein kinase complexes containing the {beta}2 regulatory subunit are up-regulated during and contribute to adipogenesis
This study therefore sought to determine the contribution of AMPKβ subunit isoforms to adipocyte biology, focussing on adipogenesis. AMPKβ2 was the principal AMPKβ isoform in 3T3-L1 adipocytes, isolated rodent adipocytes and human subcutaneous adipose tissue, as assessed by the contribution to total cellular AMPK activity. Down-regulation of AMPKβ2 with siRNA inhibited lipid accumulation, cellular adiponectin levels and adiponectin secretion during 3T3-L1 adipogenesis, whereas down-regulation of AMPKβ1 had no effect. Incubation of 3T3-L1 cells with MT47-100 selectively inhibited AMPK complexes cont...
Source: Biochemical Journal - June 25, 2019 Category: Biochemistry Authors: Katwan, O. J., Alghamdi, F., Almabrouk, T. A., Mancini, S. J., Kennedy, S., Oakhill, J. S., Scott, J. W., Salt, I. P. Tags: Research Articles Source Type: research
Loss of GCN5L1 in cardiac cells disrupts glucose metabolism and promotes cell death via reduced Akt/mTORC2 signaling
In this study, we sought to determine the mechanism by which GCN5L1 impacts energy substrate utilization and mitochondrial health. We find that hypoxia and reoxygenation (H/R) leads to a reduction in cell viability and Akt phosphorylation in GCN5L1 knockdown AC16 cardiomyocytes, in parallel with elevated glucose utilization and impaired fatty acid use. We demonstrate that glycolysis is uncoupled from glucose oxidation under normoxic conditions in GCN5L1-depleted cells. We show that GCN5L1 directly binds to the Akt-activating mTORC2 component Rictor, and that loss of Rictor acetylation is evident in GCN5L1 knockdown cells. ...
Source: Biochemical Journal - June 18, 2019 Category: Biochemistry Authors: Manning, J. R., Thapa, D., Zhang, M., Stoner, M. W., Traba, J., Corey, C., Shiva, S., Sack, M. N., Scott, I. Tags: Research Articles Source Type: research
Allosteric, transcriptional and post-translational control of mitochondrial energy metabolism
The heart is the organ with highest energy turnover rate (per unit weight) in our body. The heart relies on its flexible and powerful catabolic capacity to continuously generate large amounts of ATP utilizing many energy substrates including fatty acids, carbohydrates (glucose and lactate), ketones and amino acids. The normal health mainly utilizes fatty acids (40–60%) and glucose (20–40%) for ATP production while ketones and amino acids have a minor contribution (10–15% and 1–2%, respectively). Mitochondrial oxidative phosphorylation is the major contributor to cardiac energy production (95%) while...
Source: Biochemical Journal - June 18, 2019 Category: Biochemistry Authors: Karwi, Q. G., Jörg, A. R., Lopaschuk, G. D. Tags: Review Articles Source Type: research
Binding properties of the quaternary assembly protein SPAG1
In this study, we have investigated the role of TPR domains of SPAG1 in the recruitment of HSP chaperones by combining biochemical assays, ITC, NMR spectroscopy and molecular dynamics (MD) simulations. First, we propose that only two, out of the three TPR domains, are able to recruit the protein chaperones HSP70 and HSP90. We then focused on one of these TPR domains and elucidated its 3D structure using NMR spectroscopy. Relying on an NMR-driven docking approach and MD simulations, we deciphered its binding interface with the C-terminal tails of both HSP70 and HSP90. Finally, we addressed the biological function of SPAG1 a...
Source: Biochemical Journal - June 13, 2019 Category: Biochemistry Authors: Chagot, M.-E., Dos Santos Morais, R., Dermouche, S., Lefebvre, D., Manival, X., Chipot, C., Dehez, F., Quinternet, M. Tags: Research Articles Source Type: research
Hsp70 molecular chaperones: multifunctional allosteric holding and unfolding machines
The Hsp70 family of chaperones works with its co-chaperones, the nucleotide exchange factors and J-domain proteins, to facilitate a multitude of cellular functions. Central players in protein homeostasis, these jacks-of-many-trades are utilized in a variety of ways because of their ability to bind with selective promiscuity to regions of their client proteins that are exposed when the client is unfolded, either fully or partially, or visits a conformational state that exposes the binding region in a regulated manner. The key to Hsp70 functions is that their substrate binding is transient and allosterically cycles in a nucl...
Source: Biochemical Journal - June 13, 2019 Category: Biochemistry Authors: Clerico, E. M., Meng, W., Pozhidaeva, A., Bhasne, K., Petridis, C., Gierasch, L. M. Tags: Review Articles Source Type: research
Characterization of soluble CD39 (SolCD39/NTPDase1) from PiggyBac nonviral system as a tool to control the nucleotides level
Extracellular ATP (eATP) and its metabolites have emerged as key modulators of different diseases and comprise a complex pathway called purinergic signaling. An increased number of tools have been developed to study the role of nucleotides and nucleosides in cell proliferation and migration, influence on the immune system and tumor progression. These tools include receptor agonists/antagonists, engineered ectonucleotidases, interference RNAs and ectonucleotidase inhibitors that allow the control and quantification of nucleotide levels. NTPDase1 (also called apyrase, ecto-ATPase and CD39) is one of the main enzymes responsi...
Source: Biochemical Journal - June 10, 2019 Category: Biochemistry Authors: Beckenkamp, L. R., Iser, I. C., Onzi, G. R., Fontoura, D. M. S. d., Bertoni, A. P. S., Sevigny, J., Lenz, G., Wink, M. R. Tags: Research Articles Source Type: research
PP2C phosphatase Pic1 negatively regulates the phosphorylation status of Pti1b kinase, a regulator of flagellin-triggered immunity in tomato
Plant immune responses, including the production of reactive oxygen species (ROS), are triggered when pattern recognition receptors (PRRs) become activated upon detection of microbe-associated molecular patterns (MAMPs). Receptor-like cytoplasmic kinases are key components of PRR-dependent signaling pathways. In tomato, two such kinases, Pti1a and Pti1b, are important positive regulators of the plant immune response. However, it is unknown how these kinases control plant immunity at the molecular level and how their activity is regulated. To investigate these issues, we used mass spectrometry to search for interactors of P...
Source: Biochemical Journal - June 10, 2019 Category: Biochemistry Authors: Giska, F., Martin, G. B. Tags: Research Articles Source Type: research
Biochemical and structural investigation of taurine:2-oxoglutarate aminotransferase from Bifidobacterium kashiwanohense
Taurine aminotransferases catalyze the first step in taurine catabolism in many taurine-degrading bacteria and play an important role in bacterial taurine metabolism in the mammalian gut. Here, we report the biochemical and structural characterization of a new taurine:2-oxoglutarate aminotransferase from the human gut bacterium Bifidobacterium kashiwanohense (BkToa). Biochemical assays revealed high specificity of BkToa for 2-oxoglutarate as the amine acceptor. The crystal structure of BkToa in complex with pyridoxal 5'-phosphate (PLP) and glutamate was determined at 2.7 Å resolution. The enzyme forms a homodime...
Source: Biochemical Journal - June 10, 2019 Category: Biochemistry Authors: Li, M., Wei, Y., Yin, J., Lin, L., Zhou, Y., Hua, G., Cao, P., Ang, E. L., Zhao, H., Yuchi, Z., Zhang, Y. Tags: Research Articles Source Type: research
Slc25a36 modulates pluripotency of mouse embryonic stem cells by regulating mitochondrial function and glutathione level
This study improves the understanding of the function of Slc25a36, as well as the relationship of mitochondrial function with naive pluripotency maintenance and stem cell fate decision. (Source: Biochemical Journal)
Source: Biochemical Journal - June 10, 2019 Category: Biochemistry Authors: Xin, Y., Wang, Y., Zhong, L., Shi, B., Liang, H., Han, J. Tags: Research Articles Source Type: research
Zinc induces iron uptake and DMT1 expression in Caco-2 cells via a PI3K/IRP2 dependent mechanism
The absorption of iron is influenced by numerous dietary and physiological factors. We have previously demonstrated that zinc treatment of intestinal cells increases iron absorption via induction of the apical membrane iron transporter divalent metal ion transporter-1 (DMT1). To better understand the mechanisms of zinc-induced iron absorption, we have studied the effect of zinc on iron uptake, iron transporter and iron regulatory protein (IRP 1 and 2) expression and the impact of the PI3K pathway in differentiated Caco-2 cells, an intestinal cell culture model. We found that zinc induces DMT1 protein and mRNA expression. Z...
Source: Biochemical Journal - June 10, 2019 Category: Biochemistry Authors: Kondaiah, P., Aslam, M. F., Mashurabad, P. C., Sharp, P. A., Pullakhandam, R. Tags: Research Articles Source Type: research
Retraction: Bax channel triplet: co-operativity and voltage gating
(Source: Biochemical Journal)
Source: Biochemical Journal - May 30, 2019 Category: Biochemistry Authors: Lin, S. H., Cherian, N., Wu, B., Phee, H., Cho, C., Colombini, M. Tags: Retractions Source Type: research
Structural basis for the C-domain-selective angiotensin-converting enzyme inhibition by bradykinin-potentiating peptide b (BPPb)
We present the BPPb N-domain structure in comparison with the previously reported BPPb C-domain structure and highlight key differences in peptide interactions with the S4 to S9 subsites. This suggests the involvement of these subsites in conferring C-domain-selective BPPb binding, in agreement with the mutagenesis results where unique residues governing differences in active site exposure, lid structure and dynamics between the two domains were the major drivers for C-domain-selective BPPb binding. Mere disruption of BPPb interactions with unique S2 and S4 subsite residues, which synergistically assist in BPPb binding, wa...
Source: Biochemical Journal - May 30, 2019 Category: Biochemistry Authors: Sturrock, E. D., Lubbe, L., Cozier, G. E., Schwager, S. L. U., Arowolo, A. T., Arendse, L. B., Belcher, E., Acharya, K. R. Tags: Research Articles Source Type: research
Plastidic glucose-6-phosphate dehydrogenases are regulated to maintain activity in the light
Glucose-6-phosphate dehydrogenase (G6PDH) can initiate the glucose-6-phosphate (G6P) shunt around the Calvin–Benson cycle. To understand the regulation of flux through this pathway, we have characterized the biochemical parameters and redox regulation of the three functional plastidic isoforms of Arabidopsis G6PDH. When purified, recombinant proteins were measured, all three exhibited significant substrate inhibition by G6P but not NADP+, making the determination of enzyme kinetic parameters complex. We found that the half-saturation concentration of G6PDH isoform 1 is increased under reducing conditions. The other t...
Source: Biochemical Journal - May 30, 2019 Category: Biochemistry Authors: Preiser, A. L., Fisher, N., Banerjee, A., Sharkey, T. D. Tags: Research Articles Source Type: research
Tissue-specific characterization of mitochondrial branched-chain keto acid oxidation using a multiplexed assay platform
Alterations to branched-chain keto acid (BCKA) oxidation have been implicated in a wide variety of human diseases, ranging from diabetes to cancer. Although global shifts in BCKA metabolism—evident by gene transcription, metabolite profiling, and in vivo flux analyses have been documented across various pathological conditions, the underlying biochemical mechanism(s) within the mitochondrion remain largely unknown. In vitro experiments using isolated mitochondria represent a powerful biochemical tool for elucidating the role of the mitochondrion in driving disease. Such analyses have routinely been utilized across di...
Source: Biochemical Journal - May 30, 2019 Category: Biochemistry Authors: Goldberg, E. J., Buddo, K. A., McLaughlin, K. L., Fernandez, R. F., Pereyra, A. S., Psaltis, C. E., Lin, C.-T., Hagen, J. T., Boykov, I. N., Nguyen, T. K., Gowdy, K. M., Ellis, J. M., Neufer, P. D., McClung, J. M., Fisher-Wellman, K. H. Tags: Research Articles Source Type: research
