Plasma membrane calcium pumps (PMCAs) sustain a primary transport system for the specific removal of cytosolic calcium ions from eukaryotic cells. PMCAs are characterized by the presence of a C-terminal domain referred to as a regulatory domain. This domain is target of several regulatory mechanisms: activation by Ca²+-calmodulin complex and acidic phospholipids, phosphorylation by kinase A and C, proteolysis by calpain and oligomerization. As far as oligomerization is concerned, the C-terminal domain seems to be crucial for this process. We have cloned the C-terminal domain of the human PMCA isoform 1b, and characterized its properties in solution. The expressed protein maintains its tendency to oligomerize in aqueous solutions, but it is dissociated by amphipathic molecules such as diacylglycerol and sodium dodecyl sulphate. The presence of sodium dodecyl sulphate stabilizes the domain as a compact structure in monomeric form retaining the secondary structure elements, as shown by small angle neutron scattering and circular dichroism measurements. The importance of oligomerization for the regulation of PMCA activity and intracellular calcium concentration is discussed.
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http://dx.doi.org/10.1016/j.abb.2010.11.017 | DOI Listing |
Microbiol Spectr
January 2025
Department of Infection Biology, Institute of Medicine, University of Tsukuba, Ibaraki, Japan.
synthesizes aromatic amino acids (AAAs) through the common pathway to produce the precursor, chorismate, and the three terminal pathways to convert chorismate into Phe, Tyr, and Trp. also imports exogenous AAAs through five transporters. GcvB small RNA post-transcriptionally regulates more than 50 genes involved in amino acid uptake and biosynthesis in , but the full extent of GcvB regulon is still underestimated.
View Article and Find Full Text PDFFront Oncol
January 2025
State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China.
Objective: The current clinical data regarding the re-administration of PARPi maintenance therapy in platinum sensitive recurrent ovarian cancer (PSROC) is limited. This study aims to investigate the efficacy and associated factors of PARPi re-maintenance therapy in PSROC patients in China.
Methods: In this study, there were 201 patients with PSROC who had received maintenance therapy previously and achieved complete or partial response after platinum-based chemotherapy upon recurrence.
Unlabelled: SYNGAP1 is a key Ras-GAP protein enriched at excitatory synapses, with mutations causing intellectual disability and epilepsy in humans. Recent studies have revealed that in addition to its role as a negative regulator of G-protein signaling through its GAP enzymatic activity, SYNGAP1 plays an important structural role through its interaction with post-synaptic density proteins. Here, we reveal that intrinsic excitability deficits and seizure phenotypes in heterozygous Syngap1 knockout (KO) mice are differentially dependent on Syngap1 GAP activity.
View Article and Find Full Text PDFOur current understanding of protein folding is based predominantly on studies of small (<150 aa) proteins that refold reversibly from a chemically denatured state. As protein length increases, the competition between off-pathway misfolding and on-pathway folding likewise increases, creating a more complex energy landscape. Little is known about how intermediates populated during the folding of larger proteins affect navigation of this more complex landscape.
View Article and Find Full Text PDFCytotechnology
April 2025
Department of Genetics, Osmania University, Hyderabad, Telangana State India.
Targeting tumor angiogenesis with safe endogenous protein inhibitors is a promising therapeutic approach despite the plethora of the first line of emerging chemotherapeutic drugs. The extracellular matrix network in the blood vessel basement membrane and growth factors released from endothelial and tumor cells promote the neovascularization which supports the tumor growth. Contrastingly, small cleaved cryptic fragments of the C-terminal non collagenous domains of the same basement membrane display antiangiogenic effect.
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