51
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Bennett AF, Baines AJ. Bundling of microtubules by synapsin 1. Characterization of bundling and interaction of distinct sites in synapsin 1 head and tail domains with different sites in tubulin. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 206:783-92. [PMID: 1318836 DOI: 10.1111/j.1432-1033.1992.tb16985.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Synapsin 1 is a nerve terminal phosphoprotein whose role seems to encompass the linking of small synaptic vesicles to the cytoskeleton. Synapsin 1 can join small synaptic vesicles to neuronal spectrin, microfilaments and microtubules; it can also bundle microtubules and microfilaments. In this paper, the mode of interaction between synapsin 1 and microtubules has been investigated. Bundling is shown to be highly cooperative: the apparent Hill coefficient is 3.06 +/- 0.3, and bundling is half-maximal at 0.63 +/- 0.02 microM. Bundling occurs either when whole synapsin 1 preparations (containing monomers and oligomers) or when monomeric synapsin 1 is added to microtubules. However, it is not clear that synapsin 1 remains monomeric in the presence of microtubules. Synapsin 1-microtubule mixtures contain two types of filament. One type is characterised by microtubules often with synapsin 1 bound to their surface. The other type is composed of filaments of diameter 15 +/- 5 nm. This filament type is granular and made up in part of 14-nm-diameter particles. These dimensions are consistent with their being made up of polymerised synapsin 1. It is possible that microtubules induce the polymerisation of synapsin 1. Synapsin 1 had independent tubulin binding sites in the N-terminal head domain and in the C-terminal tail domain. Whole synapsin 1 can interact with tubulin after it has been digested to remove the tubulin C terminus (des-C-terminal tubulin). The interaction of des-C-terminal tubulin with synapsin 1 appears to be via the head domain, since 125I-des-C-terminal tubulin only shows specific binding to the head domain on gel blots. By contrast intact tubulin binds to both head and tail domains. Binding to the tail domain can be inhibited by a synthetic peptide representing the microtubule-associated protein 2 (MAP2) binding site of class II beta tubulin. These results suggest a model for microtubule bundling by synapsin 1 in which independent sites in the head and tail domains of synapsin 1 cross-link microtubules by interactions with two distinct sites in tubulin.
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Affiliation(s)
- A F Bennett
- Biological Laboratory, University of Kent, Canterbury, England
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52
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Giri PR, Marietta CA, Higuchi S, Kincaid RL. Molecular and phylogenetic analysis of calmodulin-dependent protein phosphatase (calcineurin) catalytic subunit genes. DNA Cell Biol 1992; 11:415-24. [PMID: 1318721 DOI: 10.1089/dna.1992.11.415] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In the mammalian brain, there are multiple catalytic subunits for the Ca(2+)- and calmodulin-dependent protein phosphatase [also called protein phosphatase 2B (PP-2B) and calcineurin] that are derived from two structural genes. The coding sequences of these two genes are distinguished by the absence (PP2B alpha 1) or the presence (PP2B alpha 2) of an amino terminus containing polyproline. Both of these genes can produce intragenic isoforms through alternative splicing. In the present study, a potential phylogenetic relationship of these genes was inferred from analysis of genomic DNA and from studies of mRNA and protein expression. Southern blot analysis showed unique restriction fragments for both genes in seven mammalian species; however, in organisms from two nonmammalian vertebrates (chicken and lizard), hybridization was observed only for PP2B alpha 1. In agreement with these results, Northern blots of mammalian brain RNA showed transcripts for both genes, with about two to three times more of the PP2B alpha 1 mRNAs, whereas in chicken and lizard, only PP2B alpha 1 transcripts were detected. An analysis of protein expression by two-dimensional electrophoresis was also consistent with these findings. For the purified mammalian brain protein, eight to ten variants were observed with isoelectric points of 5.2-5.8; immunoblot analysis using anti-peptide antibodies indicated that the majority of these were PP2B alpha 1 forms. In chicken brain, multiple isoforms were recognized by antibodies against the PP2B alpha 1 forms, but no reactivity was seen with those against the PP2B alpha 2 forms. Taken together, these findings suggest that: (i) in mammals, the predominant catalytic subunit isoforms in brain are PP2B alpha 1 products and (ii) the gene for the polyproline-containing catalytic subunit of calmodulin-dependent phosphatase (PP2B alpha 2) may have evolved after the avian/reptilian branching point, perhaps to carry out a role(s) of particular significance in mammals.
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Affiliation(s)
- P R Giri
- Section on Immunology, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD 20852
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53
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Leachman SA, Gallagher PJ, Herring BP, McPhaul MJ, Stull JT. Biochemical properties of chimeric skeletal and smooth muscle myosin light chain kinases. J Biol Chem 1992; 267:4930-8. [PMID: 1371510 PMCID: PMC2836765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023] Open
Abstract
The molecular and biochemical properties of myosin light chain kinases from chicken skeletal and smooth muscle were investigated by recombinant DNA techniques. Deletion of the amino-terminal region of either the smooth or skeletal muscle myosin light chain kinase resulted in a decrease in Vmax with no significant change in Km values for light chain substrates. Skeletal/smooth muscle chimeric kinases were inactive when a 65-residue region amino-terminal of the catalytic core was exchanged between the two forms. Changing alanine 494 to glutamic acid within this region in the chicken skeletal muscle myosin light chain kinase increased the Km values for light chains 10-fold. These results are consistent with the hypothesis that the region amino-terminal of the catalytic core in myosin light chain kinases is involved in light chain recognition. A skeletal muscle kinase which contained the smooth muscle calmodulin binding domain remained regulated by Ca2+/calmodulin. Thus, the calmodulin binding domains of smooth and skeletal muscle myosin light chain kinases share structural elements necessary for regulation.
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Affiliation(s)
- S A Leachman
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas 75235
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54
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Mangels L, Gnegy M. Carbachol stimulates binding of a photoreactive calmodulin derivative to calmodulin-binding proteins in intact SK-N-SH human neuroblastoma cells. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42631-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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55
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Leachman S, Gallagher P, Herring B, McPhaul M, Stull J. Biochemical properties of chimeric skeletal and smooth muscle myosin light chain kinases. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42920-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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56
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Abstract
Calmodulin, as a major intracellular calcium-binding protein, regulates many Ca(2+)-dependent enzymes and plays an important role in a wide spectrum of cellular functions of the eukaryotes. Interaction between calmodulin and human lactoferrin, a 78 kDa protein with antibacterial properties, was found in the presence of Ca2+ using (i) a method for the detection of calmodulin binding proteins with biotinylated calmodulin, (ii) affinity chromatography on an agarose-calmodulin column with subsequent detection by an enzyme-linked immunosorbent assay (ELISA). The binding of calmodulin to lactoferrin blocked the ability of lactoferrin to agglutinate Micrococcus lysodeikticus.
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Affiliation(s)
- A de Lillo
- Departamento de Biología Funcional, Facultad de Medicina, Universidad de Oviedo, Spain
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57
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McGarrity TJ, Peiffer LP, Billingsley ML. Interspecies comparison of calmodulin binding proteins throughout the gastrointestinal tract: comparison with human colon adenomas and adenocarcinomas. Gut 1991; 32:1121-6. [PMID: 1955165 PMCID: PMC1379371 DOI: 10.1136/gut.32.10.1121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Calmodulin is an ubiquitous cytoplasmic protein which mediates many of the actions of calcium on intestinal tissue including regulation of growth and differentiation of normal and neoplastic cells. Using a biotinylated calmodulin overlay system, we compared the pattern of calmodulin binding proteins throughout the gastrointestinal tract of mice, rats, rabbits, and humans, and in human colonic adenomas and adenocarcinomas. A common calmodulin binding protein of 67 kDa was found in membrane and cytosolic fractions of oesophagus, stomach, proximal and distal small intestine, and colon from all four species. In human tissue this 67 kDa protein was present in greatest concentration in stomach tissue. Furthermore, a 67 kDa binding protein was the major calmodulin binding protein from human stomach and ileum as determined by ion exchange and calmodulin affinity chromatography. A similar pattern of binding proteins was noted between rabbit and human cytosolic fractions; proteins of 60/67 kDa and 105 kDa were present in stomach tissue. A 94 kDa protein was present in samples of rabbit and human ileum but not of mouse or rat. A similar pattern of calmodulin binding proteins was seen in normal and neoplastic large bowel tissue, apart from one of nine adenocarcinomas, where a distinct 54 kDa band was noted in both cytosolic and membrane fractions. The results of this study show interspecies and organ differences between calmodulin binding proteins, but suggest that a 67 kDa protein is the major binding protein present throughout normal gastro-intestinal tract and neoplastic human tissue.
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Affiliation(s)
- T J McGarrity
- Department of Medicine, University Hospital, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
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58
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Polli JW, Kincaid RL, Torris J, Billingsley ML. Expression of calmodulin-dependent enzymes in developing rat striatum is not affected by perturbation of dopaminergic systems. Synapse 1991; 9:136-43. [PMID: 1821485 DOI: 10.1002/syn.890090208] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Transsynaptic regulation is one mechanism that controls expression of several calmodulin (CaM)-dependent enzymes. This observation and the demonstration that expression of several CaM-dependent enzymes in developing striatum occurred with a spatial and temporal pattern similar to that seen for dopamine and tyrosine hydroxylase suggested that the nigrostriatal pathway may influence the expression of CaM-binding proteins (CaM-BPs) during striatal development. Therefore, the possible role of nigrostriatal dopamine systems regulating the expression of CaM-dependent enzymes was studied in Sprague-Dawley rats by using surgical hemitransections of brain, 6-hydroxydopamine lesions, and chronic haloperidol treatments. Alterations in CaM-BP expression following perturbation of the developing nigrostriatal tract were analyzed by using immunoblots, biotinylated CaM overlays, and enzyme assays. The extent of nigrostriatal lesions was assessed by using depletion of immunoreactive tyrosine hydroxylase levels in striatum. All three experimental paradigms failed to alter the normal developmental expression of CaM-dependent enzymes. From these results we conclude that the increased expression of CaM-dependent enzymes during striatal development is not directly dependent on synaptic input from the nigrostriatal dopamine system.
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Affiliation(s)
- J W Polli
- Department of Pharmacology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
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59
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Higuchi S, Tamura J, Giri P, Polli J, Kincaid R. Calmodulin-dependent protein phosphatase from Neurospora crassa. Molecular cloning and expression of recombinant catalytic subunit. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)55242-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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60
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Fairley JA, Scott GA, Jensen KD, Goldsmith LA, Diaz LA. Characterization of keratocalmin, a calmodulin-binding protein from human epidermis. J Clin Invest 1991; 88:315-22. [PMID: 1711543 PMCID: PMC296035 DOI: 10.1172/jci115294] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Using affinity-purified calmodulin-binding proteins from human epidermis we have developed a monoclonal IgM antibody, ROC 129.1, to a human desmosomal calcmodulin-binding protein. This antibody reacts with a submembranous 250-kD protein from human keratinocytes and stains human epidermis in a "cell-surface pattern". Permeability studies indicated that the epitope with which this monoclonal reacts is on the inner surface of the cell membrane. Immunoelectronmicroscopy localized the antigen to the desmosome. The epitope is restricted to stratified squamous epithelia and arises between 8-12 wk of fetal development. This desmosomal calmodulin-binding protein, which we have termed keratocalmin, may be involved in the calcium-regulated assembly of desmosomes.
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Affiliation(s)
- J A Fairley
- Department of Dermatology, Medical College of Wisconsin, Milwaukee 53226
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61
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Polli JW, Billingsley ML. Preparation, characterization and biological properties of biotinylated derivatives of calmodulin. Biochem J 1991; 275 ( Pt 3):733-43. [PMID: 1645521 PMCID: PMC1150115 DOI: 10.1042/bj2750733] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Biotinylated derivatives of calmodulin (CaM) were prepared and their biological properties characterized by using enzyme assays, affinity and hydrophobic-interaction chromatography. Several N-hydroxysuccinimidobiotin derivatives [sulphosuccinimidobiotin (sulpho-NHS) and sulphosuccinimido-6-(biotinamido)hexanoate (BNHS-LC)] differing in spacer arm length were used to modify CaM. The shorter-spacer-arm CaM derivative (sulpho-CaM) activated CaM-dependent cyclic nucleotide phosphodiesterase and CaM-dependent protein kinase II; preincubation with avidin blocked its ability to activate these enzymes. The extended-spacer-arm derivative (BNHS-LC-CaM) activated CaM-dependent enzymes both in the presence and in the absence of avidin, suggesting that the longer spacer arm diminished steric effects from avidin preincubation. Other biotinylated CaM derivatives were prepared with biotinylated tyrosine and/or histidine residues (diazobenzoylbiocytin; DBB-CaM) or nucleophilic sites (photobiotin acetate; photo-CaM). These derivatives activated CaM-dependent enzymes in the presence and in the absence of avidin. Oriented affinity columns were constructed with covalently immobilized avidin complexed to each biotinylated CaM derivative. The chromatographic profiles obtained revealed that each column interacted with a specific subset of CaM-binding proteins. Elution profiles of biotinyl CaM derivatives on phenyl-Sepharose hydrophobic-interaction chromatography suggested that several derivatives displayed diminished binding to the matrix in the presence of Ca2+. Development and characterization of a series of biotinylated CaM molecules can be used to identify domains of CaM that interact with specific CaM-dependent enzymes.
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Affiliation(s)
- J W Polli
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey 17033
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62
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Schmidt HH, Pollock JS, Nakane M, Gorsky LD, Förstermann U, Murad F. Purification of a soluble isoform of guanylyl cyclase-activating-factor synthase. Proc Natl Acad Sci U S A 1991; 88:365-9. [PMID: 1703296 PMCID: PMC50811 DOI: 10.1073/pnas.88.2.365] [Citation(s) in RCA: 283] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The soluble form of guanylyl cyclase-activating-factor (GAF) synthase from rat cerebellum was purified to homogeneity by sequential affinity chromatographic steps on adenosine 2',5'-bisphosphate (2',5'-ADP)-Sepharose and calmodulin-agarose. Enzyme activity during purification was bioassayed by the L-arginine-, NADPH-, and Ca2+/calmodulin-dependent formation of a plasma membrane-permeable nitric oxide-like factor that stimulated soluble guanylyl cyclase in RFL-6 cells. With calmodulin and NADPH as cofactors, purified soluble GAF synthase induced an increase of 1.05 mumol of cGMP per 10(6) RFL-6 cells per 3 min per mg of protein. The coproduct of this signal-transduction pathway appeared to be L-citrulline. GAF synthase catalyzed the conversion of 107 nmol of L-arginine into L-citrulline per min per mg of protein. Based on these assays, this represents a purification of GAF synthase of approximately 10,076- and 8925-fold with recoveries of 16% and 19%, respectively. Rechromatography of the purified enzyme on Mono P (isoelectric point = 6.1 +/- 0.3), Mono Q, and Superose 12 or 6 resulted in no further purification or increase in specific activity. A Stokes radius of 7.9 +/- 0.3 nm and a sedimentation coefficient s20,w of 7.8 +/- 0.2 S were used to calculate a molecular mass of about 279 +/- 25 kDa for the native enzyme. SDS/PAGE revealed a single protein band with a molecular mass of about 155 +/- 3 kDa. These data suggest that soluble GAF synthase purified from rat cerebellum is a homodimer of 155-kDa subunits and that enzyme activity is dependent upon the presence of calmodulin.
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Affiliation(s)
- H H Schmidt
- Abbott Laboratories, Abbott Park, IL 60064-3500
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63
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Jefferson AB, Travis SM, Schulman H. Activation of multifunctional Ca2+/calmodulin-dependent protein kinase in GH3 cells. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52320-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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64
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Churn SB, Taft WC, Billingsley MS, Blair RE, DeLorenzo RJ. Temperature modulation of ischemic neuronal death and inhibition of calcium/calmodulin-dependent protein kinase II in gerbils. Stroke 1990; 21:1715-21. [PMID: 2264078 DOI: 10.1161/01.str.21.12.1715] [Citation(s) in RCA: 127] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We used brief bilateral carotid artery occlusion in gerbils to examine the effects of temperature on ischemia-induced inhibition of calcium/calmodulin-dependent protein kinase II activity and neuronal death. In normothermic (36 degrees C) gerbils, ischemia induced a severe loss of hippocampal CA1 pyramidal neurons measured 7 days after ischemia (28.4 neurons/mm, n = 10; control density in 10 naive gerbils 262.1 neurons/mm) and a significant decrease in forebrain calcium/calmodulin-dependent protein kinase II autophosphorylation measured 2 hours after ischemia (12.9 fmol/min, n = 6; control phosphorylation in six naive gerbils 23.5 fmol/min). The effect of temperature on these indicators of ischemic damage was examined by adjusting intracerebral temperature before and during the ischemic insult. Hyperthermic (39 degrees C) gerbils showed almost complete loss of neurons in the CA1 region (3.0 neurons/mm, n = 11) and extension of neuronal death into the CA2, CA3, and CA4 regions. In addition, hyperthermia exacerbated ischemia-induced inhibition of calcium/calmodulin-dependent protein kinase II activity (4.2 fmol/min, n = 6). Hypothermia (32 degrees C) protected against ischemia-induced CA1 pyramidal cell damage (257.0 neurons/mm, n = 20) and inhibition of calcium/calmodulin-dependent protein kinase II activity (26.0 fmol/min, n = 6). Our results are consistent with the hypothesis that loss of calcium/calmodulin-dependent protein kinase II activity may be a critical event in the development of ischemia-induced cell death.
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Affiliation(s)
- S B Churn
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond
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65
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Subramanyam C, Honn SC, Reed WC, Reddy GP. Nuclear localization of 68 kDa calmodulin-binding protein is associated with the onset of DNA replication. J Cell Physiol 1990; 144:423-8. [PMID: 2202742 DOI: 10.1002/jcp.1041440309] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In Chinese hamster embryo fibroblast cells, an increase in intracellular calmodulin levels coincided with the nuclear localization of a calmodulin-binding protein of about 68 kDa as the cells progressed from G1 to S phase. When cells were limited from entering into S phase, by omitting insulin a defined medium, intracellular CaM levels did not increase and the 68 kDa calmodulin-binding protein was completely absent from the nuclei. Corresponding to the nuclear localization of calmodulin and the 68 kDa calmodulin-binding protein in S phase cells, there was a dramatic increase in DNA polymerase and thymidine kinase activities in the nuclei of S phase cells as compared to G1 phase cells. In addition, the 68 kDa calmodulin-binding protein, along with calmodulin, is observed to be an integral component of replitase complex responsible for nuclear DNA replication in S phase cells. These observations point to the association of calmodulin and calmodulin-binding protein(s) with the replication machinery responsible for nuclear DNA replication during S phase. A possible regulatory role of these proteins in the onset of DNA replication and cell proliferation is discussed.
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Affiliation(s)
- C Subramanyam
- Department of Obstetrics and Gynecology, University of Virginia Diabetes Center, Charlottesville 22906
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66
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Kincaid RL, Giri PR, Higuchi S, Tamura J, Dixon SC, Marietta CA, Amorese DA, Martin BM. Cloning and characterization of molecular isoforms of the catalytic subunit of calcineurin using nonisotopic methods. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38593-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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67
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Members of the 70-kilodalton heat shock protein family contain a highly conserved calmodulin-binding domain. Mol Cell Biol 1990. [PMID: 2154682 DOI: 10.1128/mcb.10.3.1234] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The 70-kilodalton heat shock protein (hsp70) family members appear to be essential components in a number cellular protein-protein interactions. We report here on the characterization of a new functional region in hsp70, a calmodulin-binding site. We have identified a 21-amino-acid sequence within the hsp70 protein that contains a calmodulin-binding domain. The peptide formed a potential amphipathic alpha helix and bound calmodulin with high affinity. Comparison of amino acid homology of this calmodulin-binding sequence with analogous hsp70 sequences from other species showed a high degree of conservation.
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68
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Stevenson MA, Calderwood SK. Members of the 70-kilodalton heat shock protein family contain a highly conserved calmodulin-binding domain. Mol Cell Biol 1990; 10:1234-8. [PMID: 2154682 PMCID: PMC361007 DOI: 10.1128/mcb.10.3.1234-1238.1990] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The 70-kilodalton heat shock protein (hsp70) family members appear to be essential components in a number cellular protein-protein interactions. We report here on the characterization of a new functional region in hsp70, a calmodulin-binding site. We have identified a 21-amino-acid sequence within the hsp70 protein that contains a calmodulin-binding domain. The peptide formed a potential amphipathic alpha helix and bound calmodulin with high affinity. Comparison of amino acid homology of this calmodulin-binding sequence with analogous hsp70 sequences from other species showed a high degree of conservation.
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Affiliation(s)
- M A Stevenson
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115
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69
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Pennypacker KR, Kincaid RL, Polli JW, Billingsley ML. Expression of calmodulin-dependent phosphodiesterase, calmodulin-dependent protein phosphatase, and other calmodulin-binding proteins in human SMS-KCNR neuroblastoma cells. J Neurochem 1989; 52:1438-48. [PMID: 2540270 DOI: 10.1111/j.1471-4159.1989.tb09191.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Calmodulin (CaM)-dependent enzymes, such as CaM-dependent phosphodiesterase (CaM-PDE), CaM-dependent protein phosphatase (CN), and CaM-dependent protein kinase II (CaM kinase II), are found in high concentrations in differentiated mammalian neurons. In order to determine whether neuroblastoma cells express these CaM-dependent enzymes as a consequence of cellular differentiation, a series of experiments was performed on human SMS-KCNR neuroblastoma cells; these cells morphologically differentiate in response to retinoic acid and phorbol esters [12-O-tetradecanoylphorbol 13-acetate (TPA)]. Using biotinylated CaM overlay procedures, immunoblotting, and protein phosphorylation assays, we found that SMS-KCNR cells expressed CN and CaM-PDE, but did not appear to have other neuronal CaM-binding proteins. Exposure to retinoic acid, TPA, or conditioned media from human HTB-14 glioma cells did not markedly alter the expression of CaM-binding proteins; 21-day treatment with retinoic acid, however, did induce expression of novel CaM-binding proteins of 74 and 76 kilodaltons. Using affinity-purified polyclonal antibodies, CaM-PDE immunoreactivity was detected as a 75-kilodalton peptide in undifferentiated cells, but as a 61-kilodalton peptide in differentiated cells. CaM kinase II activity and subunit autophosphorylation was not evident in either undifferentiated or neurite-bearing cells; however, CaM-dependent phosphatase activity was seen. Immunoblot analysis with affinity-purified antibodies against CN indicated that this enzyme was present in SMS-KCNR cells regardless of their state of differentiation. Although SMS-KCNR cells did not show a complete pattern of neuronal CaM-binding proteins, particularly because CaM kinase II activity was lacking, they may be useful models for examination of CaM-PDE and CN expression. It is possible that CaM-dependent enzymes can be used as sensitive markers for terminal neuronal differentiation.
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Affiliation(s)
- K R Pennypacker
- Department of Pharmacology, Milton S. Hershey Medical Center, The Pennsylvania State University College of Medicine, Hershey 17033
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70
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Abstract
Calmodulin, an acidic protein that binds calcium with high affinity, has multiple roles in the activation of many enzymes involved in cellular regulation of eukaryotes. In this study we show that calmodulin binding to hen egg-white lysozyme, in a Ca2+-dependent way, was observed using electroblots incubated with biotinylated calmodulin and detected with avidin-alkaline phosphatase or for affinity chromatography on a gel calmodulin column. Antimicrobial activity of lysozyme was not modified in the presence of Ca2+-calmodulin.
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Affiliation(s)
- J F Fierro
- Departamento de Biologia Funcional, Facultad de Medicina, Universidad de Oviedo, Spain
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71
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72
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Kincaid RL, Martin BM. Characterization of the calmodulin-binding domain of calcineurin deduced from a complementary DNA clone. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1989; 255:347-58. [PMID: 2559598 DOI: 10.1007/978-1-4684-5679-0_38] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- R L Kincaid
- Section on Immunology, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892
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73
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Mann DM, Brandt P, Sisken B, Vanaman TC. Identification of a synaptic membrane-localized isoform of the calcium-pumping ATPase. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1989; 255:71-8. [PMID: 2533457 DOI: 10.1007/978-1-4684-5679-0_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- D M Mann
- University of Kentucky School of Medicine, Department of Biochemistry, Lexington 40536
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74
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Kincaid RL, Nightingale MS, Martin BM. Characterization of a cDNA clone encoding the calmodulin-binding domain of mouse brain calcineurin. Proc Natl Acad Sci U S A 1988; 85:8983-7. [PMID: 2848250 PMCID: PMC282646 DOI: 10.1073/pnas.85.23.8983] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A cDNA clone corresponding to a portion of the catalytic subunit of calmodulin (CaM)-dependent phosphoprotein phosphatase (calcineurin) was isolated from a murine brain library by expression vector immunoscreening. A beta-galactosidase fusion protein that reacted on Western blots with anti-calcineurin antibodies and biotinylated CaM was purified in preparative amounts using CaM-Sepharose affinity chromatography. Partial digestion of the hybrid protein with Staphylococcus aureus V-8 protease produced several immunoreactive peptides that appeared identical to fragments generated from authentic brain calcineurin. The 1111-base-pair (bp) EcoRI insert contained an open reading frame encoding a protein of 35 kDa followed by a 190-bp 3' noncoding region; seven peptides obtained by partial amino acid sequencing of the bovine brain enzyme were found in the deduced sequence. A domain approximately 12 kDa from the carboxyl terminus was deduced to be the CaM-binding site based on consensus structural features and a sequence of seven amino acids highly related to smooth muscle myosin light-chain kinase. Two regions with identity to protein phosphatases 1 and 2A were found in the amino half of the cloned sequence; however, the intervening sequence contained apparent insertions, suggesting splicing of subdomains. Thus, the structure of calcineurin is chimeric, consisting of conserved catalytic elements and a regulatory CaM-binding domain.
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Affiliation(s)
- R L Kincaid
- Section on Immunology, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892
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75
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Patel K, Strong PN, Dubowitz V, Dunn MJ. Calmodulin-binding profiles for nebulin and dystrophin in human skeletal muscle. FEBS Lett 1988; 234:267-71. [PMID: 3292289 DOI: 10.1016/0014-5793(88)80095-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Nebulin and dystrophin are two high-molecular-mass skeletal muscle proteins that have both been associated with the defective gene in Duchenne muscular dystrophy, although the function of neither protein is known. Other high-molecular-mass, calmodulin-binding proteins have recently been implicated in regulating calcium release from skeletal muscle. Western blots of human skeletal muscle biopsy samples were probed with biotinylated calmodulin; nebulin was identified as a prominent high-molecular-mass calmodulin-binding protein but dystrophin did not bind detectable amounts of biotinylated calmodulin. Dystrophin was absent in a Duchenne muscle biopsy.
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Affiliation(s)
- K Patel
- Jerry Lewis Muscle Research Centre, Department of Paediatrics, Royal Postgraduate Medical School, London, England
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76
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Pennypacker KR, Kyritsis A, Chader GJ, Billingsley ML. Calmodulin-binding proteins in human Y-79 retinoblastoma and HTB-14 glioma cell lines. J Neurochem 1988; 50:1648-54. [PMID: 2834519 DOI: 10.1111/j.1471-4159.1988.tb03055.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The Y-79 human retinoblastoma cell line has been used as a model system for studying differentiation of primitive neuroectodermal cells into either glial-like (glial fibrillary acidic protein positive) or neuron-like (neuron-specific enolase-positive) cells. To determine whether Y-79 retinoblastoma cells express neuronotypic calmodulin-binding proteins, Y-79 cells were either treated with butyrate or dibutyryl cyclic AMP (dbcAMP) in serum-containing medium or were maintained in serum-free media. Using a biotinylated calmodulin blot overlay technique, we found that Y-79 cells treated with dbcAMP or butyrate expressed low levels of membrane-bound calmodulin-binding proteins of 150, 147, 127, and 126 kilodaltons (kDa); butyrate-treated cells also expressed a calmodulin-binding peptide of 135 kDa. Since butyrate treatment of Y-79 cells induces the expression and the secretion of interphotoreceptor retinoid-binding protein (IRBP, 140 kDa), we tested the hypothesis that the calmodulin-binding protein of 135 kDa induced by butyrate treatment was IRBP. Purified bovine IRBP did not bind calmodulin; further, the 135-kDa calmodulin binding protein was not immunoreactive with antisera directed against IRBP. Since dbcAMP and butyrate induce some glial-like characteristics in Y-79 cells, we compared the calmodulin-binding protein pattern in these cells with that seen in human HTB-14 glioma cells. The HTB-14 line did not express calmodulin-binding proteins, even after treatments with agents that induce morphologic change in these cells. Thus, we conclude that Y-79 cells express membrane-bound calmodulin-binding proteins, but in a pattern different from that seen with adult, differentiated neurons or from human HTB-14 glioma cells.
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Affiliation(s)
- K R Pennypacker
- Department of Pharmacology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
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77
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Brennan DP, Levine MA. Characterization of soluble and particulate parathyroid hormone receptors using a biotinylated bioactive hormone analog. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47865-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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78
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Kincaid RL, Balaban CD, Billingsley ML. Differential localization of calmodulin-dependent enzymes in rat brain: evidence for selective expression of cyclic nucleotide phosphodiesterase in specific neurons. Proc Natl Acad Sci U S A 1987; 84:1118-22. [PMID: 3029762 PMCID: PMC304374 DOI: 10.1073/pnas.84.4.1118] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
High-affinity antibodies against calmodulin (CaM)-dependent cyclic nucleotide phosphodiesterase and protein phosphatase (calcineurin) were purified and characterized. Rabbit anti-phosphodiesterase antibody did not react with other phosphodiesterases or with the regulatory subunits of cAMP-dependent protein kinase. Affinity-purified goat anti-calcineurin antibody recognized both the 61-kDa catalytic subunit and the 18-kDa Ca2+-binding subunit of the phosphatase. Neither antibody reacted with CaM, several CaM-binding proteins (calmodulin-dependent protein kinase, myosin light chain kinase, fodrin), or other cytosolic proteins from brain. The antibodies were used to compare the cellular localization of these two CaM-dependent enzymes in rat brain. Both calcineurin and phosphodiesterase were found predominantly in nerve cells; however, phosphodiesterase was restricted to very specific neuronal populations. Phosphodiesterase was prominent in the somatic cytoplasm and dendrites of regional output neurons--e.g., cerebellar Purkinje cells and hippocampal and cortical pyramidal cells. The extensive and uniform staining in the dendrites was consistent with postsynaptic localization and suggested an important function for this enzyme in neurons that integrate multiple convergent inputs. Calcineurin was present in virtually all classes of neurons, with immunoreactivity confined primarily to cell bodies. Both diffuse cytoplasmic staining and characteristic punctate staining of cell bodies were observed; the latter suggested compartmentalization of calcineurin at or near the plasma membrane. The results of this study demonstrate that calcineurin and phosphodiesterase are differentially localized in the central nervous system. Thus, the expression and compartmentalization of CaM-binding proteins may be highly regulated and specific for particular differentiated nerve cell types.
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79
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Glätzer KH, Kloetzel PM. Differential chromosomal distribution of ribonucleoprotein antigens in nuclei of Drosophila spermatocytes. J Cell Biol 1986; 103:2113-9. [PMID: 3536959 PMCID: PMC2114595 DOI: 10.1083/jcb.103.6.2113] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The ribonucleoprotein (RNP) composition of the active Y chromosomal structures in spermatocyte nuclei of Drosophila hydei has been investigated using the anti-RNP antibodies Dm 28K2 and pp60 as a probe. Antibody Dm 28K2 was raised against an RNP protein of cytoplasmic RNP particles in D. melanogaster cells, while antibody pp60 was raised against a pre-messenger RNP fraction from oocytes of Xenopus laevis. Both antibodies detect nuclear RNP (nRNP) antigens of D. hydei. This is shown by CsCl density centrifugation of nRNP from D. hydei cells and immunoblotting across the density gradient. Dm 28K2 and pp60 recognize antigens of nRNP complexes which band at a characteristic buoyant density of approximately 1.4 g/cm3 in CsCl. By indirect immunofluorescence we observe that the nRNP complexes identified by Dm 28K2 are localized at only two of the five Y chromosomal loop structures which are named according to their distinct morphology. Dm 28K2 decorates RNPs within the "clubs," within the cones, and within the matrix of the "pseudonucleolus." Ultrastructural bodies that are candidates for this immunoreaction are RNP granules that resemble the so-called perichromatin granules. Antibody pp60 recognizes RNP complexes close to the axes of the active Y chromatin. In the "pseudonucleolus" it can be shown that the structures recognized by pp60 are quite distinct from those detected by Dm 28K2. Thus, the "pseudonucleolus" is a striking example for the presence of different RNP populations within a same defined nuclear compartment. Together with previous results (Glätzer, K. H., 1984, Mol. Gen. Genet., 196:236-243), our data represent evidence that the morphological and apparently functional differences between the active Y chromosomal loops, which are involved in male fertility, are caused by the presence of qualitatively and possibly also functionally different RNP populations within these nuclear compartments. Because both RNP antigens are discussed in the literature in connection with repressed mRNP the observed cross-reaction of the respective antibodies in D. hydei suggests a more general and important function of these proteins in the RNA metabolism of eukaryotic cells.
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