scholarly journals Calcium-Dependent Translocation of S100B Is Facilitated by Neurocalcin Delta

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 227
Author(s):  
Jingyi Zhang ◽  
Anuradha Krishnan ◽  
Hao Wu ◽  
Venkat Venkataraman
Keyword(s):  
Glial Cells ◽  
Calcium Binding ◽  
Living Cells ◽  
Bimolecular Fluorescence Complementation ◽  
Calcium Dependent ◽  
Potential Biomarker ◽  
Neuronal Calcium Sensor Protein ◽  
Golgi Network ◽  
Calcium Elevation

S100B is a calcium-binding protein that governs calcium-mediated responses in a variety of cells—especially neuronal and glial cells. It is also extensively investigated as a potential biomarker for several disease conditions, especially neurodegenerative ones. In order to establish S100B as a viable pharmaceutical target, it is critical to understand its mechanistic role in signaling pathways and its interacting partners. In this report, we provide evidence to support a calcium-regulated interaction between S100B and the neuronal calcium sensor protein, neurocalcin delta both in vitro and in living cells. Membrane overlay assays were used to test the interaction between purified proteins in vitro and bimolecular fluorescence complementation assays, for interactions in living cells. Added calcium is essential for interaction in vitro; however, in living cells, calcium elevation causes translocation of the NCALD-S100B complex to the membrane-rich, perinuclear trans-Golgi network in COS7 cells, suggesting that the response is independent of specialized structures/molecules found in neuronal/glial cells. Similar results are also observed with hippocalcin, a closely related paralog; however, the interaction appears less robust in vitro. The N-terminal region of NCALD and HPCA appear to be critical for interaction with S100B based on in vitro experiments. The possible physiological significance of this interaction is discussed.

Disruption of Golgi structure and function in mammalian cells expressing a mutant dynamin

2000 ◽  
Vol 113 (11) ◽  
pp. 1993-2002 ◽  
Author(s):  
H. Cao ◽  
H.M. Thompson ◽  
E.W. Krueger ◽  
M.A. McNiven
Keyword(s):  
Mammalian Cells ◽  
Living Cells ◽  
Dominant Negative ◽  
Coated Vesicle ◽  
Large Numbers ◽  
Golgi Structure ◽  
And Function ◽  
Golgi Network ◽  
Mutant Cells

The large GTPase dynamin is a mechanoenzyme that participates in the scission of nascent vesicles from the plasma membrane. Recently, dynamin has been demonstrated to associate with the Golgi apparatus in mammalian cells by morphological and biochemical methods. Additional studies using a well characterized, cell-free assay have supported these findings by demonstrating a requirement for dynamin function in the formation of clathrin-coated, and non-clathrin-coated vesicles from the trans-Golgi network (TGN). In this study, we tested if dynamin participates in Golgi function in living cells through the expression of a dominant negative dynamin construct (K44A). Cells co-transfected to express this mutant dynamin and a GFP-tagged Golgi resident protein (TGN38) exhibit Golgi structures that are either compacted, vesiculated, or tubulated. Electron microscopy of these mutant cells revealed large numbers of Golgi stacks comprised of highly tubulated cisternae and an extraordinary number of coated vesicle buds. Cells expressing mutant dynamin and GFP-tagged VSVG demonstrated a marked retention (8- to 11-fold) of the nascent viral G-protein in the Golgi compared to control cells. These observations in living cells are consistent with previous morphological and in vitro studies demonstrating a role for dynamin in the formation of secretory vesicles from the TGN.

scholarly journals Tyrosine nitration on calmodulin enhances calcium-dependent association and activation of nitric-oxide synthase

2019 ◽  
Vol 295 (8) ◽  
pp. 2203-2211 ◽  
Author(s):  
Joseph J. Porter ◽  
Hyo Sang Jang ◽  
Mohammad Mahfuzul Haque ◽  
Dennis J. Stuehr ◽  
Ryan A. Mehl
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Calcium Binding ◽  
Vascular Dysfunction ◽  
Post Translational Modification ◽  
Calcium Dependent ◽  
Genetic Code Expansion ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Production of reactive oxygen species caused by dysregulated endothelial nitric-oxide synthase (eNOS) activity is linked to vascular dysfunction. eNOS is a major target protein of the primary calcium-sensing protein calmodulin. Calmodulin is often modified by the main biomarker of nitroxidative stress, 3-nitrotyrosine (nitroTyr). Despite nitroTyr being an abundant post-translational modification on calmodulin, the mechanistic role of this modification in altering calmodulin function and eNOS activation has not been investigated. Here, using genetic code expansion to site-specifically nitrate calmodulin at its two tyrosine residues, we assessed the effects of these alterations on calcium binding by calmodulin and on binding and activation of eNOS. We found that nitroTyr–calmodulin retains affinity for eNOS under resting physiological calcium concentrations. Results from in vitro eNOS assays with calmodulin nitrated at Tyr-99 revealed that this nitration reduces nitric-oxide production and increases eNOS decoupling compared with WT calmodulin. In contrast, calmodulin nitrated at Tyr-138 produced more nitric oxide and did so more efficiently than WT calmodulin. These results indicate that the nitroTyr post-translational modification, like tyrosine phosphorylation, can impact calmodulin sensitivity for calcium and reveal Tyr site-specific gain or loss of functions for calmodulin-induced eNOS activation.

scholarly journals Calcium-dependent and -independent interactions of the S100 protein family

2006 ◽  
Vol 396 (2) ◽  
pp. 201-214 ◽  
Author(s):  
Liliana Santamaria-Kisiel ◽  
Anne C. Rintala-Dempsey ◽  
Gary S. Shaw
Keyword(s):  
Protein Interactions ◽  
Calcium Binding ◽  
S100 Protein ◽  
Cytoskeletal Proteins ◽  
S100 Proteins ◽  
Target Proteins ◽  
Calcium Dependent ◽  
Ef Hand

The S100 proteins comprise at least 25 members, forming the largest group of EF-hand signalling proteins in humans. Although the proteins are expressed in many tissues, each S100 protein has generally been shown to have a preference for expression in one particular tissue or cell type. Three-dimensional structures of several S100 family members have shown that the proteins assume a dimeric structure consisting of two EF-hand motifs per monomer. Calcium binding to these S100 proteins, with the exception of S100A10, results in an approx. 40° alteration in the position of helix III, exposing a broad hydrophobic surface that enables the S100 proteins to interact with a variety of target proteins. More than 90 potential target proteins have been documented for the S100 proteins, including the cytoskeletal proteins tubulin, glial fibrillary acidic protein and F-actin, which have been identified mostly from in vitro experiments. In the last 5 years, efforts have concentrated on quantifying the protein interactions of the S100 proteins, identifying in vivo protein partners and understanding the molecular specificity for target protein interactions. Furthermore, the S100 proteins are the only EF-hand proteins that are known to form both homo- and hetero-dimers, and efforts are underway to determine the stabilities of these complexes and structural rationales for their formation and potential differences in their biological roles. This review highlights both the calcium-dependent and -independent interactions of the S100 proteins, with a focus on the structures of the complexes, differences and similarities in the strengths of the interactions, and preferences for homo- compared with hetero-dimeric S100 protein assembly.

scholarly journals A Functional Role for the GCC185 Golgin in Mannose 6-Phosphate Receptor Recycling

2006 ◽  
Vol 17 (10) ◽  
pp. 4353-4363 ◽  
Author(s):  
Jonathan V. Reddy ◽  
Alondra Schweizer Burguete ◽  
Khambhampaty Sridevi ◽  
Ian G. Ganley ◽  
Ryan M. Nottingham ◽  
...  
Keyword(s):  
Living Cells ◽  
Receptor Recycling ◽  
Transport Vesicles ◽  
Function Loss ◽  
Transport Vesicle ◽  
Enhanced Secretion ◽  
Mannose 6 Phosphate ◽  
Golgi Network ◽  
Specific Pathway

Mannose 6-phosphate receptors (MPRs) deliver newly synthesized lysosomal enzymes to endosomes and then recycle to the Golgi. MPR recycling requires Rab9 GTPase; Rab9 recruits the cytosolic adaptor TIP47 and enhances its ability to bind to MPR cytoplasmic domains during transport vesicle formation. Rab9-bearing vesicles then fuse with the trans-Golgi network (TGN) in living cells, but nothing is known about how these vesicles identify and dock with their target. We show here that GCC185, a member of the Golgin family of putative tethering proteins, is a Rab9 effector that is required for MPR recycling from endosomes to the TGN in living cells, and in vitro. GCC185 does not rely on Rab9 for its TGN localization; depletion of GCC185 slightly alters the Golgi ribbon but does not interfere with Golgi function. Loss of GCC185 triggers enhanced degradation of mannose 6-phosphate receptors and enhanced secretion of hexosaminidase. These data assign a specific pathway to an interesting, TGN-localized protein and suggest that GCC185 may participate in the docking of late endosome-derived, Rab9-bearing transport vesicles at the TGN.

MRP8 and MRP14 control microtubule reorganization during transendothelial migration of phagocytes

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 4260-4268 ◽  
Author(s):  
Thomas Vogl ◽  
Stephan Ludwig ◽  
Matthias Goebeler ◽  
Anke Strey ◽  
Irmgard S. Thorey ◽  
...  
Keyword(s):  
Calcium Binding ◽  
S100 Protein ◽  
Transendothelial Migration ◽  
Mitogen Activated Protein Kinase ◽  
Binding Partner ◽  
Calcium Dependent ◽  
Mitogen Activated Protein

Abstract MRP14 (S100A9) is the major calcium-binding protein of neutrophils and monocytes. Targeted gene disruption reveals an essential role of this S100 protein for transendothelial migration of phagocytes. The underlying molecular mechanism comprises major alterations of cytoskeletal metabolism. MRP14, in complex with its binding partner MRP8 (S100A8), promotes polymerization of microtubules. MRP14 is specifically phosphorylated by p38 mitogen-activated protein kinase (MAPK). This phosphorylation inhibits MRP8/MRP14-induced tubulin polymerization. Phosphorylation of MRP14 is antagonistically regulated by binding of MRP8 and calcium. The biologic relevance of these findings is confirmed by the fact that MAPK p38 fails to stimulate migration of MRP14-/- granulocytes in vitro and MRP14-/- mice show a diminished recruitment of granulocytes into the granulation tissue during wound healing in vivo. MRP14-/- granulocytes contain significantly less polymerized tubulin, which subsequently results in minor activation of Rac1 and Cdc42 after stimulation of p38 MAPK. Thus, the complex of MRP8/MRP14 is the first characterized molecular target integrating MAPK- and calcium-dependent signals during migration of phagocytes.

scholarly journals Flagellar Radial Spoke Protein 2 Is a Calmodulin Binding Protein Required for Motility in Chlamydomonas reinhardtii

2004 ◽  
Vol 3 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Pinfen Yang ◽  
Chun Yang ◽  
Winfield S. Sale
Keyword(s):  
Calcium Binding ◽  
Regulatory Subunit ◽  
Dependent Manner ◽  
Radial Spoke ◽  
Calcium Dependent ◽  
Calmodulin Binding ◽  
Morphological Studies ◽  
Radial Spokes

ABSTRACT Genetic and morphological studies have revealed that the radial spokes regulate ciliary and flagellar bending. Functional and biochemical analysis and the discovery of calmodulin in the radial spokes suggest that the regulatory mechanism involves control of axonemal protein phosphorylation and calcium binding to spoke proteins. To identify potential regulatory proteins in the radial spoke, in-gel kinase assays were performed on isolated axonemes and radial spoke fractions. The results indicated that radial spoke protein 2 (RSP2) can bind ATP and transfer phosphate in vitro. RSP2 was cloned and mapped to the PF24 locus, a gene required for motility. Sequencing revealed that pf24 contains a point mutation converting the first ATG to ATA, resulting in only trace amounts of RSP2 and confirming the RSP2 mapping. Surprisingly, the sequence does not include signature domains for conventional kinases, indicating that RSP2 may not perform as a protein kinase in vivo. However, the predicted RSP2 protein sequence contains Ca2+-dependent calmodulin binding motifs and a GAF domain, a domain found in diverse signaling proteins for binding small ligands including cyclic nucleotides. As predicted from the sequence, recombinant RSP2 binds calmodulin in a calcium-dependent manner. We postulate that RSP2 is a regulatory subunit of the radial spoke involved in localization of calmodulin for control of motility.

scholarly journals Anti-Semaphorin 4D Rescues Motor, Cognitive and Respiratory Phenotypes in a Rett Syndrome Mouse Model

2021 ◽  
Vol 22 (17) ◽  
pp. 9465
Author(s):  
Yilin Mao ◽  
Elizabeth E. Evans ◽  
Vikas Mishra ◽  
Leslie Balch ◽  
Allison Eberhardt ◽  
...  
Keyword(s):  
Mouse Model ◽  
Rett Syndrome ◽  
Glial Cells ◽  
Calcium Binding ◽  
Neurodevelopmental Disorder ◽  
Neurological Dysfunction ◽  
Effective Treatment Option ◽  
Antibody Treatment ◽  
Semaphorin 4D

Rett syndrome is a neurodevelopmental disorder caused by mutations of the methyl-CpG binding protein 2 gene. Abnormal physiological functions of glial cells contribute to pathogenesis of Rett syndrome. Semaphorin 4D (SEMA4D) regulates processes central to neuroinflammation and neurodegeneration including cytoskeletal structures required for process extension, communication, and migration of glial cells. Blocking SEMA4D-induced gliosis may preserve normal glial and neuronal function and rescue neurological dysfunction in Rett syndrome. We evaluated the pre-clinical therapeutic efficacy of an anti-SEMA4D monoclonal antibody in the Rett syndrome Mecp2T158A transgenic mouse model and investigated the contribution of glial cells as a proposed mechanism of action in treated mice and in primary glial cultures isolated from Mecp2T158A/y mutant mice. SEMA4D is upregulated in neurons while glial fibrillary acidic protein and ionized calcium binding adaptor molecule 1-positive cells are upregulated in Mecp2T158A/y mice. Anti-SEMA4D treatment ameliorates Rett syndrome-specific symptoms and improves behavioural functions in both pre-symptomatic and symptomatic cohorts of hemizygous Mecp2T158A/y male mice. Anti-SEMA4D also reduces astrocyte and microglia activation in vivo. In vitro experiments demonstrate an abnormal cytoskeletal structure in mutant astrocytes in the presence of SEMA4D, while anti-SEMA4D antibody treatment blocks SEMA4D–Plexin B1 signaling and mitigates these abnormalities. These results suggest that anti-SEMA4D immunotherapy may be an effective treatment option to alleviate symptoms and improve cognitive and motor function in Rett syndrome.

scholarly journals The Variable Domain of a Plant Calcium-dependent Protein Kinase (CDPK) Confers Subcellular Localization and Substrate Recognition for NADPH Oxidase

2013 ◽  
Vol 288 (20) ◽  
pp. 14332-14340 ◽  
Author(s):  
Shuta Asai ◽  
Tatsushi Ichikawa ◽  
Hironari Nomura ◽  
Michie Kobayashi ◽  
Yusuke Kamiyoshihara ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Nadph Oxidase ◽  
Subcellular Localization ◽  
Expression System ◽  
Calcium Dependent ◽  
Dependent Protein ◽  
Golgi Network ◽  
Respiratory Burst Oxidase

Calcium-dependent protein kinases (CDPKs) are Ca2+ sensors that regulate diverse biological processes in plants and apicomplexans. However, how CDPKs discriminate specific substrates in vivo is still largely unknown. Previously, we found that a potato StCDPK5 is dominantly localized to the plasma membrane and activates the plasma membrane NADPH oxidase (RBOH; for respiratory burst oxidase homolog) StRBOHB by direct phosphorylation of the N-terminal region. Here, we report the contribution of the StCDPK5 N-terminal variable (V) domain to activation of StRBOHB in vivo using heterologous expression system in Nicotiana benthamiana. Mutations of N-terminal myristoylation and palmitoylation sites in the V domain eliminated the predominantly plasma membrane localization and the capacity of StCDPK5 to activate StRBOHB in vivo. A tomato SlCDPK2, which also contains myristoylation and palmitoylation sites in its N terminus, phosphorylated StRBOHB in vitro but not in vivo. Functional domains responsible for activation and phosphorylation of StRBOHB were identified by swapping regions for each domain between StCDPK5 and SlCDPK2. The substitution of the V domain of StCDPK5 with that of SlCDPK2 abolished the activation and phosphorylation abilities of StRBOHB in vivo and relocalized the chimeric CDPK to the trans-Golgi network, as observed for SlCDPK2. Conversely, SlCDPK2 substituted with the V domain of StCDPK5 localized to the plasma membrane and activated StRBOHB. These results suggest that the V domains confer substrate specificity in vivo by dictating proper subcellular localization of CDPKs.

Neural Stem Cells to Glial Cells an Important Factor for Brain Injury

2020 ◽  
Author(s):  
Prithiv K R Kumar
Keyword(s):  
Stem Cells ◽  
Central Nervous System ◽  
Nervous System ◽  
Neural Stem Cells ◽  
Glial Cells ◽  
Brain Injuries ◽  
The Body ◽  
The Central Nervous System ◽  
Near Future

Stem cells have the capacity to differentiate into any type of cell or organ. Stems cell originate from any part of the body, including the brain. Brain cells or rather neural stem cells have the capacitive advantage of differentiating into the central nervous system leading to the formation of neurons and glial cells. Neural stem cells should have a source by editing DNA, or by mixings chemical enzymes of iPSCs. By this method, a limitless number of neuron stem cells can be obtained. Increase in supply of NSCs help in repairing glial cells which in-turn heal the central nervous system. Generally, brain injuries cause motor and sensory deficits leading to stroke. With all trials from novel therapeutic methods to enhanced rehabilitation time, the economy and quality of life is suppressed. Only PSCs have proven effective for grafting cells into NSCs. Neurons derived from stem cells is the only challenge that limits in-vitro usage in the near future.

Overexpression of p62 Induces Autophagy and Promotes Proliferation, Migration and Invasion of Nasopharyngeal Carcinoma Cells through Promoting ERK Signaling Pathway

2020 ◽  
Vol 20 (8) ◽  
pp. 624-637 ◽  
Author(s):  
Qiong Wu ◽  
Manlin Xiang ◽  
Kun Wang ◽  
Zhen Chen ◽  
Lu Long ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Clinical Analysis ◽  
Carcinoma Cells ◽  
Immunofluorescent Staining ◽  
Clinicopathological Parameters ◽  
Migration And Invasion ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Potential Biomarker

Background: Increasing evidence has shown that p62 plays an important role in tumorigenesis. However, relatively little is known about the association between p62 and tumor invasion and metastasis; in addition, its role in NPC (nasopharyngeal carcinoma, NPC) has been rarely investigated. Objective: To investigate the effect of p62 on tumorigenesis and metastasis in nasopharyngeal carcinoma. Methods: Western blotting, immunofluorescent staining and immunohistochemistry were used to evaluate p62 protein expression. Subsequently, cell viability, colony formation, migration, invasion and autophagy assays were performed. anti-p62 autoantibodies in sera were detected by ELISA. These data were correlated with clinicopathological parameters. Results: We confirmed that p62 was significantly up-regulated in NPC tissues. Furthermore, high expression of p62 was observed in NPC cell lines, and especially in the highly metastatic 5-8F cells. In vitro, down-regulation of p62 inhibited proliferation, clone forming ability, autophagy, migration, and invasion in 5-8F cells, whereas p62 overexpression resulted in the opposite effects in 6-10B cells. Moreover, we confirmed that p62 promotes NPC cell proliferation, migration, and invasion by activating ERK (extracellular signal-regulated kinase, ERK). Clinical analysis indicated that high p62 expression correlates with lymph node and distant metastasis (P<0.05). Serum anti-p62 autoantibodies were increased in NPC patients and levels were associated with metastasis. Conclusion : Our data establish p62 targeting ERK as potential determinant in the NPC, which supplies a new pathway to treat NPC. Furthermore, p62 is a potential biomarker which might be closely related to the tumorigenesis and metastasis in NPC.

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