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Hydrocarbon Uptake and Utilization by Streptomyces Strains
Published in Donald L. Wise, Debra J. Trantolo, Edward J. Cichon, Hilary I. Inyang, Ulrich Stottmeister, Remediation Engineering of Contaminated Soils, 2000
György Barabás, András Penyige, István Szabó, György Vargha, Sándor Damjanovich, János Matkó, János Szöllósi, Anita Mátyus, Samir S. Radwan, Tadashi Hirano
GTP-binding proteins (GBP) were first recognized in eukaryotic cells. A common characteristic of these proteins is that they bind and also hydrolyze GTP due to their intrinsic GTPase activity (7,8). GBPs are involved in a variety of cellular processes, such as signal transduction, differentiation, cell division, vesicular fusion, and the regulation of the activity of a number of enzymes (7,9-113). Two classes of this superfamily of proteins could be distinguished, e.g., the classical membrane-associated heterotrimer G proteins and the "small" (21-30 kDa) GBPs (7,10).
Imaging Cell Adhesion and Migration
Published in Margarida M. Barroso, Xavier Intes, In Vivo, 2020
Chandrani Mondal, Julie Di Martino, Jose Javier Bravo-Cordero
RhoGTPase activation plays a major role in regulating the steps of the cell motility cycle. GTPases cycle between an inactive state bound to guanosine diphosphate (GDP) and an active state bound to guanosine triphosphate (GTP), which can bind to effectors and activate downstream signaling (Figure 13.2a). GTPase activation is driven by guanine nucleotide exchange factors (GEFs) and deactivation by GTPase activating proteins (GAPs). During the early 2000s, the development of biosensors to study the activation of Rho GTPase signaling pathways in living cells by using FRET constituted a major scientific development in the field. These new tools allowed for the study of GTPase signaling with high spatiotemporal resolution during cell migration. Several groups developed single-chain biosensors containing the following: two fluorescent molecules (e.g. a FRET pair, such as CFP and YFP, or any of their variants) separated by a linker, a C-terminal GTPase protein, and an N-terminal fragment of a GTPase effector that can only bind to the GTPase in its active state (GTP-bound) (Bravo-Cordero et al., 2013b) (Figure 13.2b). The design of these sensors has been optimized for different GTPases to improve FRET measurements (Aoki and Matsuda, 2009; Bravo-Cordero et al., 2011; Komatsu et al., 2011; Hanna et al., 2014; Moshfegh et al., 2014; Wu et al., 2015; Miskolci et al., 2016). When the GTPase is activated (by the exchange of GDP for GTP), it can bind the GTPase effector, resulting in a structural change that brings the two fluorescent molecules together, thus decreasing their distance and increasing the FRET signal. The sensitized FRET emission signal emitted by the acceptor when the donor is excited is used to calculate FRET (Spiering et al., 2013; Donnelly et al., 2014).
Articular Cartilage Development
Published in Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi, Articular Cartilage, 2017
Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi
Rho family small GTPases are activated by switching from an inactive GDP-bound molecule to an active GTP-bound form. Switching to the active form is controlled by guanine nucleotide exchange factors (GEFs), while switching to the inactive form is regulated by GTPase activating proteins (GAPs). GEFs and GAPs are under the control of a multitude of cell surface receptors, including integrins, serine/threonine and tyrosine kinase receptors, and GPCRs. They link extracellular matrix signaling to changes in the cytoskeleton and cell shape.
Ultrasound-assisted green synthesis of triazole-based azomethine/thiazolidin-4-one hybrid inhibitors for cancer therapy through targeting dysregulation signatures of some Rab proteins
Published in Green Chemistry Letters and Reviews, 2023
Aboubakr H. Abdelmonsef, Ahmed M. El-Saghier, Asmaa M. Kadry
Cancer is characterized by uncontrolled cell growth with metastasizes to other organs inside the body (1). Rab proteins are widely expressed in various human cancers (2–4). They are essential regulators of cell cycle progression and are responsible for gene expression (5). Rab proteins work as sensitive molecular switch existing either in an active GDP-bound form or an active GTP-bound form. Exchange from GDP to GTP is catalyzed by the guanidine exchange factor (GEF), leading to activation in response to various upstream signals. On the other hand, GTPase-activating protein (GAP) increases the intrinsic GTPase activity, resulting in the inactivation of the protein (3,4,6). The upregulation of the selected Rab proteins namely Rab2a, Rab25, Rab5, and Rab35 is linked with various human cancers such as breast, ovarian, lung, and leukemia, respectively (5,7,8). Therefore, targeting Rab proteins is an important strategy for the prevention and treatment of cancer.