Organelle autoregulation--stress responses in the ER, Golgi, mitochondria and lysosome
Organelle autoregulation is a homeostatic mechanism to regulate the capacity of each organelle according to cellular demands. The endoplasmic reticulum (ER) stress response increases the expression of ER chaperones and ER-associated degradation factors when the capacity of the ER becomes insufficient, e.g. during cellular differentiation or viral propagation, and which can be restored through increased synthesis of secretory or membrane proteins. In the Golgi stress response, insufficient organelle capacity is responded to by augmentation of glycosylation enzyme expression and vesicular transport components. The mitochondr...
Source: Journal of Biochemistry - March 27, 2015 Category: Biochemistry Authors: Sasaki, K., Yoshida, H. Tags: JB Reviews Source Type: research
MAGI2/S-SCAM outside brain
Membrane-associated guanylate kinase with an inverted arrangement of protein-protein interaction domains (MAGI)2 (also called synaptic scaffolding molecule (S-SCAM), atrophin-1-interacting protein 1, activin receptor-interacting protein 1) is a scaffold protein that binds a wide variety of receptors, cell adhesion molecules and signalling molecules. It also interacts with other scaffold proteins and adaptors, and forms a protein network that supports cell junctions. As it is highly expressed in brain, the study on its roles in synaptic organization initially preceded. However, mounting evidence indicates that MAGI2/S-SCAM ...
Source: Journal of Biochemistry - March 27, 2015 Category: Biochemistry Authors: Nagashima, S., Kodaka, M., Iwasa, H., Hata, Y. Tags: JB Reviews Source Type: research
Thermodynamic analysis of unusually thermostable CutA1 protein from human brain and its protease susceptibility
Unusually stable proteins are a disadvantage for the metabolic turnover of proteins in cells. The CutA1 proteins from Pyrococcus horikoshii and from Oryza sativa (OsCutA1) have unusually high denaturation temperatures (Td) of nearly 150 and 100°C, respectively, at pH 7.0. It seemed that the CutA1 protein from the human brain (HsCutA1) also has a remarkably high stability. Therefore, the thermodynamic stabilities of HsCutA1 and its protease susceptibility were examined. The Td was remarkably high, being over 95°C at pH 7.0. The unfolding Gibbs energy ($$\Delta {G}_{{\hbox{ H }}_{\hbox{ 2 }}\hbox{ O }}^{0}$$) was 174...
Source: Journal of Biochemistry - February 24, 2015 Category: Biochemistry Authors: Bagautdinov, B., Matsuura, Y., Yamamoto, H., Sawano, M., Ogasahara, K., Takehira, M., Kunishima, N., Katoh, E., Yutani, K. Tags: Regular Papers Source Type: research
Goniothalamin enhances the ATPase activity of the molecular chaperone Hsp90 but inhibits its chaperone activity
Hsp90 is an ATP-dependent molecular chaperone that is involved in important cellular pathways such as signal transduction pathways. It is a potential cancer drug target because it plays a critical role for stabilization and activation of oncoproteins. Thus, small molecule compounds that control the Hsp90 function are useful to elucidate potential lead compounds against cancer. We studied effect of a naturally occurring styryl-lactone goniothalamin on the activity of Hsp90. Although many drugs targeting Hsp90 inhibit the ATPase activity of Hsp90, goniothalamin enhanced rather than inhibited the ATPase activity of a cyanobac...
Source: Journal of Biochemistry - February 24, 2015 Category: Biochemistry Authors: Yokoyama, Y., Ohtaki, A., Jantan, I., Yohda, M., Nakamoto, H. Tags: Regular Papers Source Type: research
Lysophosphatidylserine analogues differentially activate three LysoPS receptors
Lysophosphatidylserine (1-oleoyl-2 R-lysophosphatidylserine, LysoPS) has been shown to have lipid mediator-like actions such as stimulation of mast cell degranulation and suppression of T lymphocyte proliferation, although the mechanisms of LysoPS actions have been elusive. Recently, three G protein-coupled receptors (LPS1/GPR34, LPS2/P2Y10 and LPS3/GPR174) were found to react specifically with LysoPS, raising the possibility that LysoPS serves as a lipid mediator that exerts its role through these receptors. Previously, we chemically synthesized a number of LysoPS analogues and evaluated them as agonists for mast-cell deg...
Source: Journal of Biochemistry - February 24, 2015 Category: Biochemistry Authors: Uwamizu, A., Inoue, A., Suzuki, K., Okudaira, M., Shuto, A., Shinjo, Y., Ishiguro, J., Makide, K., Ikubo, M., Nakamura, S., Jung, S., Sayama, M., Otani, Y., Ohwada, T., Aoki, J. Tags: Regular Papers Source Type: research
Biochemical and functional characterization of Bothropoidin: the first haemorrhagic metalloproteinase from Bothrops pauloensis snake venom
We present the biochemical and functional characterization of Bothropoidin, the first haemorrhagic metalloproteinase isolated from Bothrops pauloensis snake venom. This protein was purified after three chromatographic steps on cation exchange CM-Sepharose fast flow, size-exclusion column Sephacryl S-300 and anion exchange Capto Q. Bothropoidin was homogeneous by SDS-PAGE under reducing and non-reducing conditions, and comprised a single chain of 49,558 Da according to MALDI TOF analysis. The protein presented an isoelectric point of 3.76, and the sequence of six fragments obtained by MS (MALDI TOF\TOF) showed a significant...
Source: Journal of Biochemistry - February 24, 2015 Category: Biochemistry Authors: Gomes, M. S. R., Naves de Souza, D. L., Guimaraes, D. O., Lopes, D. S., Mamede, C. C. N., Gimenes, S. N. C., Ache, D. C., Rodrigues, R. S., Yoneyama, K. A. G., Borges, M. H., de Oliveira, F., Rodrigues, V. M. Tags: Regular Papers Source Type: research
Cell models lead to understanding of multi-cellular morphogenesis consisting of successive self-construction of cells
Morphogenesis of multi-cellular organisms occurs through cell behaviours within a cell aggregate. Cell behaviours have been described using cell models involving equations of motion for cells. Cells in cell models construct shapes of the cell aggregate by themselves. Here, a history of cell models, the cell centre model and the vertex cell model, which we have constructed, are described. Furthermore, the application of these cell models is explained in detail. These cell models have been applied to transformation of cell aggregates to become spherical, formation of mammalian blastocysts and cell intercalation in elongating...
Source: Journal of Biochemistry - February 24, 2015 Category: Biochemistry Authors: Honda, H., Nagai, T. Tags: JB Review-Mathematical Modeling of Cell Behaviors during Morphogenesis Source Type: research
Models of lung branching morphogenesis
Vertebrate airway has a tree-like-branched structure. This structure is generated by repeated tip splitting, which is called branching morphogenesis. Although this phenomenon is extensively studied in developmental biology, the mechanism of the pattern formation is not well understood. Conversely, there are many tree-like structures in purely physical or chemical systems, and their pattern formation mechanisms are well-understood using mathematical models. Recent studies correlate these biological observations and mathematical models to understand lung branching morphogenesis. These models use slightly different mechanisms...
Source: Journal of Biochemistry - February 24, 2015 Category: Biochemistry Authors: Miura, T. Tags: JB Review-Mathematical Modeling of Cell Behaviors during Morphogenesis Source Type: research
Detection of ultra-low levels of DNA changes by drinking water: epidemiologically important finding
The safety of drinking water is essential to our health. In this context, the mutagenicity of water needs to be checked strictly. However, from the methodological limit, the lower concentration (less than parts per million) of mutagenicity could not be detected, though there have been of interest in the effect of less concentration mutagens. Here, we describe a highly sensitive mutation assay that detects mutagens at the ppb level, termed genome profiling-based mutation assay (GPMA). This consists of two steps; (i) Escherichia coli culture in the medium with/without mutagens and (ii) Genome profiling (GP) method (an integr...
Source: Journal of Biochemistry - January 24, 2015 Category: Biochemistry Authors: Kumari, P., Kamiseki, M., Biyani, M., Suzuki, M., Nemoto, N., Aita, T., Nishigaki, K. Tags: Regular Papers Source Type: research
The adapter protein CD2AP binds to p53 protein in the cytoplasm and can discriminate its polymorphic variants P72R
Proline-rich motifs are widely distributed in eukaryotic proteomes and are usually involved in the assembly of functional complexes through interaction with specific binding modules. The tumour - suppressor p53 protein presents a proline-rich region that is crucial for regulating apoptosis by connecting the p53 with a complex protein network. In humans, a common polymorphism determines the identity of residue 72, either proline or arginine, and affects the features of the motifs present in the polyproline domain. The two isoforms have different biochemical properties and markedly influence cancer onset and progression. In ...
Source: Journal of Biochemistry - January 24, 2015 Category: Biochemistry Authors: Panni, S., Salvioli, S., Santonico, E., Langone, F., Storino, F., Altilia, S., Franceschi, C., Cesareni, G., Castagnoli, L. Tags: Regular Papers Source Type: research
CCN family protein 2 (CCN2) promotes the early differentiation, but inhibits the terminal differentiation of skeletal myoblasts
This study clarified the CCN2 functions during myogenesis. Recombinant CCN2 (rCCN2) promoted proliferation and MyoD production in C2C12 cells and primary myoblasts, but inhibited myogenin production. In accordance with these findings, the gene expression levels of myosin heavy chain, which is a marker of terminally differentiated myoblasts and desmin, which is the main intermediate filament protein of muscle cells, were decreased by rCCN2 treatment. In vivo analyses with Ccn2-deficient skeletal muscle revealed decreased proliferating cell nuclear antigen (PCNA)/MyoD double positive cells and muscle hypoplasia. Consistent w...
Source: Journal of Biochemistry - January 24, 2015 Category: Biochemistry Authors: Nishida, T., Kubota, S., Aoyama, E., Janune, D., Lyons, K. M., Takigawa, M. Tags: Regular Papers Source Type: research
Lysophosphatidic acid as a lipid mediator with multiple biological actions
Lysophosphatidic acid (LPA) is one of the simplest glycerophospholipids with one fatty acid chain and a phosphate group as a polar head. Although LPA had been viewed just as a metabolic intermediate in de novo lipid synthetic pathways, it has recently been paid much attention as a lipid mediator. LPA exerts many kinds of cellular processes, such as cell proliferation and smooth muscle contraction, through cognate G protein-coupled receptors. Because lipids are not coded by the genome directly, it is difficult to know their patho- and physiological roles. However, recent studies have identified several key factors mediating...
Source: Journal of Biochemistry - January 24, 2015 Category: Biochemistry Authors: Aikawa, S., Hashimoto, T., Kano, K., Aoki, J. Tags: JB Special Reviews-Recent Progress in Lipid Mediators Source Type: research
Roles of prostaglandin receptors in female reproduction
Prostaglandins (PGs) have long been known to play roles in various processes of female reproduction; however, the molecular mechanisms therein remained unsolved until recently. This review summarizes the recent progress towards understanding the molecular mechanisms underlying PG actions in fertilization and parturition. A series of studies using EP2-deficient mice demonstrated that after ovulation chemokine signalling in the cumulus cells stimulates integrin activation and cumulus extracellular matrix (ECM) assembly through the RhoA/ROCK/actomyosin pathway, although excessive chemokine signalling disturbs sperm penetratio...
Source: Journal of Biochemistry - January 24, 2015 Category: Biochemistry Authors: Sugimoto, Y., Inazumi, T., Tsuchiya, S. Tags: JB Special Reviews-Recent Progress in Lipid Mediators Source Type: research
Two distinct leukotriene B4 receptors, BLT1 and BLT2
Leukotriene B4 (LTB4) is a potent inflammatory mediator derived from arachidonic acid. Two G protein-coupled receptors for LTB4 have been identified: a high-affinity receptor, BLT1, and a low-affinity receptor, BLT2. Both receptors mainly couple to pertussis toxin-sensitive Gi-like G proteins and induce cell migration. 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (12-HHT) was identified to bind BLT2 with higher affinity than LTB4. Expression of BLT1 was confirmed in type 1 helper T cells, type 2 helper T cells, type 17 helper T cells, effector CD8+ T cells, dendritic cells and osteoclasts in addition to granulocytes, eos...
Source: Journal of Biochemistry - January 24, 2015 Category: Biochemistry Authors: Yokomizo, T. Tags: JB Special Reviews-Recent Progress in Lipid Mediators Source Type: research
The protein phosphatase Siw14 controls caffeine-induced nuclear localization and phosphorylation of Gln3 via the type 2A protein phosphatases Pph21 and Pph22 in Saccharomyces cerevisiae
In this study, we show that the increased nuclear localization of Gln3 in response to caffeine caused by disruption of the SIW14 gene is dependent on the Sit4 and PP2A phosphatases. We also show that decreased phosphorylation of Gln3 caused by disruption of the SIW14 gene is completely suppressed by deletion of both PPH21 and PPH22, but only partially suppressed by deletion of SIT4. Taking these results together, we conclude that Siw14 functions upstream of Pph21 and Pph22 as an inhibitor of the phosphorylation and localization of Gln3, and that Sit4 acts independently of Siw14. (Source: Journal of Biochemistry)
Source: Journal of Biochemistry - January 5, 2015 Category: Biochemistry Authors: Numamoto, M., Sasano, Y., Hirasaki, M., Sugiyama, M., Maekawa, H., Harashima, S. Tags: Regular Papers Source Type: research
