A new multigene family encoding calcium-dependent calmodulin-binding membrane proteins of Paramecium tetraurelia

Gene ◽  
1999 ◽  
Vol 231 (1-2) ◽  
pp. 21-32 ◽  
Author(s):  
Catherine W.M. Chan ◽  
Yoshiro Saimi ◽  
Ching Kung
Keyword(s):  
Membrane Proteins ◽  
Multigene Family ◽  
Paramecium Tetraurelia ◽  
Calcium Dependent ◽  
Calmodulin Binding

scholarly journals Similarities and differences in the structure and function of 4.1G and 4.1R135, two protein 4.1 paralogues expressed in erythroid cells

2010 ◽  
Vol 432 (2) ◽  
pp. 407-416 ◽  
Author(s):  
Wataru Nunomura ◽  
Kengo Kinoshita ◽  
Marilyn Parra ◽  
Philippe Gascard ◽  
Xiuli An ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Erythroid Differentiation ◽  
Band 3 ◽  
Erythroid Cells ◽  
Protein 4.1 ◽  
Calcium Dependent ◽  
Calmodulin Binding ◽  
And Function ◽  
Glycophorin C ◽  
In Erythroid Cells

Membrane skeletal protein 4.1R is the prototypical member of a family of four highly paralogous proteins that include 4.1G, 4.1N and 4.1B. Two isoforms of 4.1R (4.1R135 and 4.1R80), as well as 4.1G, are expressed in erythroblasts during terminal differentiation, but only 4.1R80 is present in mature erythrocytes. Although the function of 4.1R isoforms in erythroid cells has been well characterized, there is little or no information on the function of 4.1G in these cells. In the present study, we performed detailed characterization of the interaction of 4.1G with various erythroid membrane proteins and the regulation of these interactions by calcium-saturated calmodulin. Like both isoforms of 4.1R, 4.1G bound to band 3, glycophorin C, CD44, p55 and calmodulin. While both 4.1G and 4.1R135 interact with similar affinity with CD44 and p55, there are significant differences in the affinity of their interaction with band 3 and glycophorin C. This difference in affinity is related to the non-conserved N-terminal headpiece region of the two proteins that is upstream of the 30 kDa membrane-binding domain that harbours the binding sites for the various membrane proteins. The headpiece region of 4.1G also contains a high-affinity calcium-dependent calmodulin-binding site that plays a key role in modulating its interaction with various membrane proteins. We suggest that expression of the two paralogues of protein 4.1 with different affinities for band 3 and glycophorin C is likely to play a role in assembly of these two membrane proteins during terminal erythroid differentiation.

Stimulation of Calmodulin Binding to Skeletal Muscle Membrane Proteins by 1,25-Dihydroxy-Vitamin D 3

1990 ◽  
Vol 45 (6) ◽  
pp. 663-670 ◽  
Author(s):  
Virginia Massheimer ◽  
Luis M. Fernandez ◽  
Ana R. de Boland
Keyword(s):  
Skeletal Muscle ◽  
Vitamin D ◽  
Membrane Proteins ◽  
Binding Proteins ◽  
Sodium Dodecyl ◽  
Muscle Membrane ◽  
Calmodulin Binding ◽  
Ca Uptake ◽  
Vitamin D 3 ◽  
Stimulation Of

Abstract Previous work has shown that 1,25-dihydroxy-vitamin D 3 rapidly increases calmodulin levels of skeletal muscle membranes without altering the muscle cell calmodulin content. Therefore, the effects of the sterol on the binding of calmodulin to specific muscle membrane proteins were investigated. Soleus muscles from vitamin D-deficient chicks were treated in vitro for short intervals (5-15 min) with physiological concentrations of 1,25-dihydroxy-vitamin D3. Proteins of mitochondria and microsomes isolated by differential centrifugation were separated on sodium dodecyl sulfate polyacrylamide gels. Calmodulin-binding proteins were identified by a [125I]calmodulin gel overlay procedure followed by autoradiography. 1,25-Dihydroxy- vitamin D3 increased the binding of labelled calmodulin to a major, calcium-independent, calmodulin-binding protein of 28 Kda localized in microsomes, and to minor calmodulin- binding proteins of 78 and 130 Kda proteins localized in mitochondria. The binding of [125I]calmodulin to these proteins was abolished by flufenazine or excess non-radioactive calmodulin. 1,25-Dihydroxy-vitamin D3 rapidly increased muscle tissue Ca uptake and cyclic AM P levels and stimulated the phosphorylation of several membrane proteins including those whose calmodulin-binding capacity potentiates. Analogously to the sterol, forskolin increased membrane calmodulin content, calmodulin binding to the 28 Kda microsomal protein and 45Ca uptake by soleus muscle preparations. Forskolin also induced a similar profile of changes in muscle membrane protein phosphorylation as the hormone. These results suggest that 1,25- dihydroxy-vitamin D 3 affects calmodulin distribution in muscle cells through cyclic AMP-dependent phosphorylation of membrane calmodulin-binding proteins. These changes may play a role in the stimulation of muscle Ca uptake by the sterol.

scholarly journals Calmodulin-dependent activation and inactivation of anoctamin calcium-gated chloride channels

2013 ◽  
Vol 142 (4) ◽  
pp. 381-404 ◽  
Author(s):  
Kerstin Vocke ◽  
Kristin Dauner ◽  
Anne Hahn ◽  
Anne Ulbrich ◽  
Jana Broecker ◽  
...  
Keyword(s):  
Splice Variant ◽  
Chloride Channels ◽  
Cell Types ◽  
Binding Motif ◽  
Binding Studies ◽  
Channel Activation ◽  
Calcium Dependent ◽  
Calmodulin Binding ◽  
Dependent Inactivation ◽  
Cl Channels

Calcium-dependent chloride channels serve critical functions in diverse biological systems. Driven by cellular calcium signals, the channels codetermine excitatory processes and promote solute transport. The anoctamin (ANO) family of membrane proteins encodes three calcium-activated chloride channels, named ANO 1 (also TMEM16A), ANO 2 (also TMEM16B), and ANO 6 (also TMEM16F). Here we examined how ANO 1 and ANO 2 interact with Ca2+/calmodulin using nonstationary current analysis during channel activation. We identified a putative calmodulin-binding domain in the N-terminal region of the channel proteins that is involved in channel activation. Binding studies with peptides indicated that this domain, a regulatory calmodulin-binding motif (RCBM), provides two distinct modes of interaction with Ca2+/calmodulin, one at submicromolar Ca2+ concentrations and one in the micromolar Ca2+ range. Functional, structural, and pharmacological data support the concept that calmodulin serves as a calcium sensor that is stably associated with the RCBM domain and regulates the activation of ANO 1 and ANO 2 channels. Moreover, the predominant splice variant of ANO 2 in the brain exhibits Ca2+/calmodulin-dependent inactivation, a loss of channel activity within 30 s. This property may curtail ANO 2 activity during persistent Ca2+ signals in neurons. Mutagenesis data indicated that the RCBM domain is also involved in ANO 2 inactivation, and that inactivation is suppressed in the retinal ANO 2 splice variant. These results advance the understanding of Ca2+ regulation in anoctamin Cl− channels and its significance for the physiological function that anoctamin channels subserve in neurons and other cell types.

scholarly journals Selective Ca2+-dependent interaction of calmodulin with the head domain of synapsin 1

1991 ◽  
Vol 275 (1) ◽  
pp. 93-97 ◽  
Author(s):  
N V Hayes ◽  
A F Bennett ◽  
A J Baines
Keyword(s):  
Regulatory Protein ◽  
Critical Element ◽  
Nerve Terminals ◽  
Calcium Dependent ◽  
Calmodulin Binding ◽  
Head Domain ◽  
N Terminus ◽  
Dependent Interaction ◽  
Synapsin 1

The calcium-dependent regulatory protein calmodulin is a critical element in the machinery regulating exocytosis at nerve terminals. Okabe & Sobue [(1987) FEBS Lett. 213, 184-188] showed that calmodulin interacts with one of the proteins intimately connected with the neuronal exocytotic process, i.e. synapsin 1. We have investigated the site at which calmodulin interacts with synapsin 1. We find that it is possible to generate chemically cross-linked Ca2(+)-dependent complexes between synapsin 1 and calmodulin in vitro, and have used covalent cross-linking in conjunction with calmodulin affinity chromatography to identify fragments of synapsin 1 that interact with calmodulin. Ca2(+)-dependent calmodulin binding is restricted to the ‘head’ domain (residues 1-453 in bovine synapsin 1). Within this domain the binding site is located in a unique 11 kDa Staphylococcus aureus V8 proteinase generated fragment. This fragment does not contain the site for cyclic-AMP-dependent phosphorylation and therefore does not represent the N-terminus of the protein.

scholarly journals Calmodulin and Calmodulin Binding Proteins in Dictyostelium: A Primer

2020 ◽  
Vol 21 (4) ◽  
pp. 1210
Author(s):  
Danton H. O’Day ◽  
Ryan J. Taylor ◽  
Michael A. Myre
Keyword(s):  
Conformational Changes ◽  
Calcium Binding ◽  
Binding Proteins ◽  
Regulatory Protein ◽  
Model Organism ◽  
Ion Binding ◽  
Calcium Dependent ◽  
Calmodulin Binding ◽  
Human Counterpart ◽  
Ef Hands

Dictyostelium discoideum is gaining increasing attention as a model organism for the study of calcium binding and calmodulin function in basic biological events as well as human diseases. After a short overview of calcium-binding proteins, the structure of Dictyostelium calmodulin and the conformational changes effected by calcium ion binding to its four EF hands are compared to its human counterpart, emphasizing the highly conserved nature of this central regulatory protein. The calcium-dependent and -independent motifs involved in calmodulin binding to target proteins are discussed with examples of the diversity of calmodulin binding proteins that have been studied in this amoebozoan. The methods used to identify and characterize calmodulin binding proteins is covered followed by the ways Dictyostelium is currently being used as a system to study several neurodegenerative diseases and how it could serve as a model for studying calmodulinopathies such as those associated with specific types of heart arrythmia. Because of its rapid developmental cycles, its genetic tractability, and a richly endowed stock center, Dictyostelium is in a position to become a leader in the field of calmodulin research.

scholarly journals Drosophilia spectrin. I. Characterization of the purified protein.

1987 ◽  
Vol 105 (5) ◽  
pp. 2095-2102 ◽  
Author(s):  
R Dubreuil ◽  
T J Byers ◽  
D Branton ◽  
L S Goldstein ◽  
D P Kiehart
Keyword(s):  
Actin Binding ◽  
Contour Length ◽  
Diagnostic Features ◽  
Calcium Dependent ◽  
Calmodulin Binding ◽  
Vertebrate Brain ◽  
Culture Cells ◽  
Drosophila Protein ◽  
Bona Fide

We purified a protein from Drosophila S3 tissue culture cells that has many of the diagnostic features of spectrin from vertebrate organisms: (a) The protein consists of two equimolar subunits (Mr = 234 and 226 kD) that can be reversibly cross-linked into a complex composed of equal amounts of the two subunits. (b) Electron microscopy of the native molecule reveals two intertwined, elongated strands with a contour length of 180 nm. (c) Antibodies directed against vertebrate spectrin react with the Drosophila protein and, similarly, antibodies to the Drosophila protein react with vertebrate spectrins. One monoclonal antibody has been found to react with both of the Drosophila subunits and with both subunits of vertebrate brain spectrin. (d) The Drosophila protein exhibits both actin-binding and calcium-dependent calmodulin-binding activities. Based on the above criteria, this protein appears to be a bona fide member of the spectrin family of proteins.

scholarly journals Calcium-Dependent Phosphorylation of Symbiosome Membrane Proteins from Nitrogen-Fixing Soybean Nodules

1991 ◽  
Vol 95 (1) ◽  
pp. 222-227 ◽  
Author(s):  
C. David Weaver ◽  
Burnette Crombie ◽  
Gary Stacey ◽  
Daniel M. Roberts
Keyword(s):  
Membrane Proteins ◽  
Nitrogen Fixing ◽  
Calcium Dependent ◽  
Symbiosome Membrane
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