Key Spec Table
|Species Reactivity||Key Applications||Host||Format||Antibody Type|
|B, H, M, Po, R, Vrt||WB, IP||M||Purified||Monoclonal Antibody|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Storage Conditions||Stable for 1 year at from date of receipt.|
|Material Size||100 µg|
|Anti-Calmodulin - 2123697||2123697|
|Anti-Calmodulin - 15341||15341|
|Anti-Calmodulin - 18130||18130|
|Anti-Calmodulin - 18823||18823|
|Anti-Calmodulin - 1969113||1969113|
|Anti-Calmodulin - 2014188||2014188|
|Anti-Calmodulin - 2073102||2073102|
|Anti-Calmodulin - 2211097||2211097|
|Reference overview||Application||Pub Med ID|
|Iqcg is essential for sperm flagellum formation in mice.|
Li, RK; Tan, JL; Chen, LT; Feng, JS; Liang, WX; Guo, XJ; Liu, P; Chen, Z; Sha, JH; Wang, YF; Chen, SJ
PloS one 9 e98053 2014
Mammalian spermatogenesis comprises three successive phases: mitosis phase, meiosis phase, and spermiogenesis. During spermiogenesis, round spermatid undergoes dramatic morphogenesis to give rise to mature spermatozoon, including the condensation and elongation of nucleus, development of acrosome, formation of flagellum, and removal of excessive cytoplasm. Although these transformations are well defined at the morphological level, the mechanisms underlying these intricate processes are largely unknown. Here, we report that Iqcg, which was previously characterized to be involved in a chromosome translocation of human leukemia, is highly expressed in the spermatogenesis of mice and localized to the manchette in developing spermatids. Iqcg knockout causes male infertility, due to severe defects of spermiogenesis and resultant total immobility of spermatozoa. The axoneme in the Iqcg knockout sperm flagellum is disorganized and hardly any typical ("9+2") pattern of microtubule arrangement could be found in Iqcg knockout spermatids. Iqcg interacts with calmodulin in a calcium dependent manner in the testis, suggesting that Iqcg may play a role through calcium signaling. Furthermore, cilia structures in the trachea and oviduct, as well as histological appearances of other major tissues, remain unchanged in the Iqcg knockout mice, suggesting that Iqcg is specifically required for spermiogenesis in mammals. These results might also provide new insights into the genetic causes of human infertility.
|Drosophila pericentrin requires interaction with calmodulin for its function at centrosomes and neuronal basal bodies but not at sperm basal bodies.|
Galletta, BJ; Guillen, RX; Fagerstrom, CJ; Brownlee, CW; Lerit, DA; Megraw, TL; Rogers, GC; Rusan, NM
Molecular biology of the cell 25 2682-94 2014
Pericentrin is a critical centrosomal protein required for organizing pericentriolar material (PCM) in mitosis. Mutations in pericentrin cause the human genetic disorder Majewski/microcephalic osteodysplastic primordial dwarfism type II, making a detailed understanding of its regulation extremely important. Germaine to pericentrin's function in organizing PCM is its ability to localize to the centrosome through the conserved C-terminal PACT domain. Here we use Drosophila pericentrin-like-protein (PLP) to understand how the PACT domain is regulated. We show that the interaction of PLP with calmodulin (CaM) at two highly conserved CaM-binding sites in the PACT domain controls the proper targeting of PLP to the centrosome. Disrupting the PLP-CaM interaction with single point mutations renders PLP inefficient in localizing to centrioles in cultured S2 cells and Drosophila neuroblasts. Although levels of PCM are unaffected, it is highly disorganized. We also demonstrate that basal body formation in the male testes and the production of functional sperm does not rely on the PLP-CaM interaction, whereas production of functional mechanosensory neurons does.
|Serotonin 5-HT3 receptor-mediated vomiting occurs via the activation of Ca2+/CaMKII-dependent ERK1/2 signaling in the least shrew (Cryptotis parva).|
Zhong, W; Hutchinson, TE; Chebolu, S; Darmani, NA
PloS one 9 e104718 2014
Stimulation of 5-HT3 receptors (5-HT3Rs) by 2-methylserotonin (2-Me-5-HT), a selective 5-HT3 receptor agonist, can induce vomiting. However, downstream signaling pathways for the induced emesis remain unknown. The 5-HT3R channel has high permeability to extracellular calcium (Ca(2+)) and upon stimulation allows increased Ca(2+) influx. We examined the contribution of Ca(2+)/calmodulin-dependent protein kinase IIα (Ca(2+)/CaMKIIα), interaction of 5-HT3R with calmodulin, and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling to 2-Me-5-HT-induced emesis in the least shrew. Using fluo-4 AM dye, we found that 2-Me-5-HT augments intracellular Ca(2+) levels in brainstem slices and that the selective 5-HT3R antagonist palonosetron, can abolish the induced Ca(2+) signaling. Pre-treatment of shrews with either: i) amlodipine, an antagonist of L-type Ca(2+) channels present on the cell membrane; ii) dantrolene, an inhibitor of ryanodine receptors (RyRs) Ca2+-release channels located on the endoplasmic reticulum (ER); iii) a combination of their less-effective doses; or iv) inhibitors of CaMKII (KN93) and ERK1/2 (PD98059); dose-dependently suppressed emesis caused by 2-Me-5-HT. Administration of 2-Me-5-HT also significantly: i) enhanced the interaction of 5-HT3R with calmodulin in the brainstem as revealed by immunoprecipitation, as well as their colocalization in the area postrema (brainstem) and small intestine by immunohistochemistry; and ii) activated CaMKIIα in brainstem and in isolated enterochromaffin cells of the small intestine as shown by Western blot and immunocytochemistry. These effects were suppressed by palonosetron. 2-Me-5-HT also activated ERK1/2 in brainstem, which was abrogated by palonosetron, KN93, PD98059, amlodipine, dantrolene, or a combination of amlodipine plus dantrolene. However, blockade of ER inositol-1, 4, 5-triphosphate receptors by 2-APB, had no significant effect on the discussed behavioral and biochemical parameters. This study demonstrates that Ca(2+) mobilization via extracellular Ca(2+) influx through 5-HT3Rs/L-type Ca(2+) channels, and intracellular Ca(2+) release via RyRs on ER, initiate Ca(2+)-dependent sequential activation of CaMKIIα and ERK1/2, which contribute to the 5-HT3R-mediated, 2-Me-5-HT-evoked emesis.
|Endothelial nitric-oxide synthase activation generates an inducible nitric-oxide synthase-like output of nitric oxide in inflamed endothelium.|
Lowry, JL; Brovkovych, V; Zhang, Y; Skidgel, RA
The Journal of biological chemistry 288 4174-93 2013
High levels of NO generated in the vasculature under inflammatory conditions are usually attributed to inducible nitric-oxide synthase (iNOS), but the role of the constitutively expressed endothelial NOS (eNOS) is unclear. In normal human lung microvascular endothelial cells (HLMVEC), bradykinin (BK) activates kinin B2 receptor (B2R) signaling that results in Ca(2+)-dependent activation of eNOS and transient NO. In inflamed HLMVEC (pretreated with interleukin-1β and interferon-γ), we found enhanced binding of eNOS to calcium-calmodulin at basal Ca(2+) levels, thereby increasing its basal activity that was dependent on extracellular l-Arg. Furthermore, B2R stimulation generated prolonged high output eNOS-derived NO that is independent of increased intracellular Ca(2+) and is mediated by a novel Gα(i)-, MEK1/2-, and JNK1/2-dependent pathway. This high output NO stimulated with BK was blocked with a B2R antagonist, eNOS siRNA, or eNOS inhibitor but not iNOS inhibitor. Moreover, B2R-mediated NO production and JNK phosphorylation were inhibited with MEK1/2 and JNK inhibitors or MEK1/2 and JNK1/2 siRNA but not with ERK1/2 inhibitor. BK induced Ca(2+)-dependent eNOS phosphorylation at Ser(1177), Thr(495), and Ser(114) in cytokine-treated HLMVEC, but these modifications were not dependent on JNK1/2 activation and were not responsible for prolonged NO output. Cytokine treatment did not alter the expression of B2R, Gα(q/11), Gα(i1,2), JNK, or eNOS. B2R activation in control endothelial cells enhanced migration, but in cytokine-treated HLMVEC it reduced migration. Both responses were NO-dependent. Understanding how JNK regulates prolonged eNOS-derived NO may provide new therapeutic targets for the treatment of disorders involving vascular inflammation.
|Metabolic regulation of CaMKII protein and caspases in Xenopus laevis egg extracts.|
McCoy, F; Darbandi, R; Chen, SI; Eckard, L; Dodd, K; Jones, K; Baucum, AJ; Gibbons, JA; Lin, SH; Colbran, RJ; Nutt, LK
The Journal of biological chemistry 288 8838-48 2013
The metabolism of the Xenopus laevis egg provides a cell survival signal. We found previously that increased carbon flux from glucose-6-phosphate (G6P) through the pentose phosphate pathway in egg extracts maintains NADPH levels and calcium/calmodulin regulated protein kinase II (CaMKII) activity to phosphorylate caspase 2 and suppress cell death pathways. Here we show that the addition of G6P to oocyte extracts inhibits the dephosphorylation/inactivation of CaMKII bound to caspase 2 by protein phosphatase 1. Thus, G6P sustains the phosphorylation of caspase 2 by CaMKII at Ser-135, preventing the induction of caspase 2-mediated apoptotic pathways. These findings expand our understanding of oocyte biology and clarify mechanisms underlying the metabolic regulation of CaMKII and apoptosis. Furthermore, these findings suggest novel approaches to disrupt the suppressive effects of the abnormal metabolism on cell death pathways.
|In vivo cross-linking reveals principally oligomeric forms of α-synuclein and β-synuclein in neurons and non-neural cells.|
Dettmer, U; Newman, AJ; Luth, ES; Bartels, T; Selkoe, D
The Journal of biological chemistry 288 6371-85 2013
Aggregation of α-synuclein (αSyn) in neurons produces the hallmark cytopathology of Parkinson disease and related synucleinopathies. Since its discovery, αSyn has been thought to exist normally in cells as an unfolded monomer. We recently reported that αSyn can instead exist in cells as a helically folded tetramer that resists aggregation and binds lipid vesicles more avidly than unfolded recombinant monomers (Bartels, T., Choi, J. G., and Selkoe, D. J. (2011) Nature 477, 107-110). However, a subsequent study again concluded that cellular αSyn is an unfolded monomer (Fauvet, B., Mbefo, M. K., Fares, M. B., Desobry, C., Michael, S., Ardah, M. T., Tsika, E., Coune, P., Prudent, M., Lion, N., Eliezer, D., Moore, D. J., Schneider, B., Aebischer, P., El-Agnaf, O. M., Masliah, E., and Lashuel, H. A. (2012) J. Biol. Chem. 287, 15345-15364). Here we describe a simple in vivo cross-linking method that reveals a major ~60-kDa form of endogenous αSyn (monomer, 14.5 kDa) in intact cells and smaller amounts of ~80- and ~100-kDa forms with the same isoelectric point as the 60-kDa species. Controls indicate that the apparent 60-kDa tetramer exists normally and does not arise from pathological aggregation. The pattern of a major 60-kDa and minor 80- and 100-kDa species plus variable amounts of free monomers occurs endogenously in primary neurons and erythroid cells as well as neuroblastoma cells overexpressing αSyn. A similar pattern occurs for the homologue, β-synuclein, which does not undergo pathogenic aggregation. Cell lysis destabilizes the apparent 60-kDa tetramer, leaving mostly free monomers and some 80-kDa oligomer. However, lysis at high protein concentrations allows partial recovery of the 60-kDa tetramer. Together with our prior findings, these data suggest that endogenous αSyn exists principally as a 60-kDa tetramer in living cells but is lysis-sensitive, making the study of natural αSyn challenging outside of intact cells.
|Identification of a calmodulin-binding domain in Sema4D that regulates its exodomain shedding in platelets.|
Mou, P; Zeng, Z; Li, Q; Liu, X; Xin, X; Wannemacher, KM; Ruan, C; Li, R; Brass, LF; Zhu, L
Blood 121 4221-30 2013
Semaphorin 4D (Sema4D) is a transmembrane protein that supports contact-dependent amplification of platelet activation by collagen before being gradually cleaved by the metalloprotease ADAM17, as we have previously shown. Cleavage releases a soluble 120-kDa exodomain fragment for which receptors exist on platelets and endothelial cells. Here we have examined the mechanism that regulates Sema4D exodomain cleavage. The results show that the membrane-proximal cytoplasmic domain of Sema4D contains a binding site for calmodulin within the polybasic region Arg762-Lys779. Coprecipitation studies show that Sema4D and calmodulin are associated in resting platelets, forming a complex that dissociates upon platelet activation by the agonists that trigger Sema4D cleavage. Inhibiting calmodulin with W7 or introducing a membrane-permeable peptide corresponding to the calmodulin-binding site is sufficient to trigger the dissociation of Sema4D from calmodulin and initiate cleavage. Conversely, deletion of the calmodulin-binding site causes constitutive shedding of Sema4D. These results show that (1) Sema4D is a calmodulin-binding protein with a site of interaction in its membrane-proximal cytoplasmic domain, (2) platelet agonists cause dissociation of the calmodulin-Sema4D complex, and (3) dissociation of the complex is sufficient to trigger ADAM17-dependent cleavage of Sema4D, releasing a bioactive fragment.
|Molecular architecture of the chick vestibular hair bundle.|
Shin, JB; Krey, JF; Hassan, A; Metlagel, Z; Tauscher, AN; Pagana, JM; Sherman, NE; Jeffery, ED; Spinelli, KJ; Zhao, H; Wilmarth, PA; Choi, D; David, LL; Auer, M; Barr-Gillespie, PG
Nature neuroscience 16 365-74 2013
Hair bundles of the inner ear have a specialized structure and protein composition that underlies their sensitivity to mechanical stimulation. Using mass spectrometry, we identified and quantified greater than 1,100 proteins, present from a few to 400,000 copies per stereocilium, from purified chick bundles; 336 of these were significantly enriched in bundles. Bundle proteins that we detected have been shown to regulate cytoskeleton structure and dynamics, energy metabolism, phospholipid synthesis and cell signaling. Three-dimensional imaging using electron tomography allowed us to count the number of actin-actin cross-linkers and actin-membrane connectors; these values compared well to those obtained from mass spectrometry. Network analysis revealed several hub proteins, including RDX (radixin) and SLC9A3R2 (NHERF2), which interact with many bundle proteins and may perform functions essential for bundle structure and function. The quantitative mass spectrometry of bundle proteins reported here establishes a framework for future characterization of dynamic processes that shape bundle structure and function.
|A new method for quantitative immunoblotting of endogenous α-synuclein.|
Newman, AJ; Selkoe, D; Dettmer, U
PloS one 8 e81314 2013
β-Sheet-rich aggregates of α-synuclein (αSyn) are the hallmark neuropathology of Parkinson's disease and related synucleinopathies, whereas the principal native structure of αSyn in healthy cells--unfolded monomer or α-helically folded oligomer--is under debate. Our recent crosslinking analysis of αSyn in intact cells showed that a large portion of endogenous αSyn can be trapped as oligomers, most notably as apparent tetramers. One challenge in such studies is accurately quantifying αSyn Western blot signals among samples, as crosslinked αSyn trends toward increased immunoreactivity. Here, we analyzed this phenomenon in detail and found that treatment with the reducible amine-reactive crosslinker DSP strongly increased αSyn immunoreactivity even after cleavage with the reducing agent β-mercaptoethanol. The effect was observed with all αSyn antibodies tested and in all sample types from human brain homogenates to untransfected neuroblastoma cells, permitting easy detection of endogenous αSyn in the latter, which had long been considered impossible. Coomassie staining of blots before and after several hours of washing revealed complete retention of αSyn after DSP/β-mercaptoethanol treatment, in contrast to a marked loss of αSyn without this treatment. The treatment also enhanced immunodetection of the homologs β- and γ-synuclein and of histones, another group of small, lysine-rich proteins. We conclude that by neutralizing positive charges and increasing protein hydrophobicity, amine crosslinker treatment promotes adhesion of αSyn to blotting membranes. These data help explain the recent report of fixing αSyn blots with paraformaldehyde after transfer, which we find produces similar but weaker effects. DSP/β-mercaptoethanol treatment of Western blots should be particularly useful to quantify low-abundance αSyn forms such as extracellular and post-translationally modified αSyn and splice variants.
|Surface expression and subunit specific control of steady protein levels by the Kv7.2 helix A-B linker.|
Aivar, P; Fernández-Orth, J; Gomis-Perez, C; Alberdi, A; Alaimo, A; Rodríguez, MS; Giraldez, T; Miranda, P; Areso, P; Villarroel, A
PloS one 7 e47263 2012
Kv7.2 and Kv7.3 are the main components of the neuronal voltage-dependent M-current, which is a subthreshold potassium conductance that exerts an important control on neuronal excitability. Despite their predominantly intracellular distribution, these channels must reach the plasma membrane in order to control neuronal activity. Thus, we analyzed the amino acid sequence of Kv7.2 to identify intrinsic signals that may control its surface expression. Removal of the interlinker connecting helix A and helix B of the intracellular C-terminus produces a large increase in the number of functional channels at the plasma membrane. Moreover, elimination of this linker increased the steady-state amount of protein, which was not associated with a decrease of protein degradation. The magnitude of this increase was inversely correlated with the number of helix A - helix B linkers present in the tetrameric channel assemblies. In contrast to the remarkable effect on the amount of Kv7.2 protein, removal of the Kv7.2 linker had no detectable impact on the steady-state levels of Kv7.3 protein.