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J Kuźnicki

Publications and source records attributed to J Kuźnicki.

At least 37 records · Page 2Linked to original sources

Characterization of calcyclin fragments obtained by CNBr-cleavage.

1. Two calcyclin fragments were obtained by CNBr-cleavage. 2. One fragment represented N-terminal end of a molecule (residues 1-56), and another one a C-terminal end (residues 57-89). 3. Properties of intact calcyclin such as binding of calcium, binding to hydrophobic resins and interaction with calcyclin specific antibodies were not retained by these fragments. 4. However, both fragments were able to form dimers and higher forms of aggregates as seen for uncleaved calcyclin. 5. This indicates that both halves of the molecule contain the regions responsible for non-covalent interaction which might participate in dimer formation.

Amino Acid Sequence↗

Calcyclin--Ca(2+)-binding protein homologous to glial S-100 beta is present in neurones.

The aim of this work was to confirm the presence of calcylin in brain and to identify calcyclin positive cells. Calcyclin was identified in brain soluble proteins that were bound to phenyl-sepharose in a calcium dependent fashion. Specific antibodies against calcylin were found to stain subsets of brain neurones such as neurones in Ammons horn of hippocampus, granule cells in cerebellum, and neurones in brain stem. Glial cells which contain large amounts of S-100 beta protein were calcyclin negative. These results indicate that calcyclin is present in neurones, but not in glial cells.

Animals↗

Calcyclin as a marker of human epithelial cells and fibroblasts.

The distribution of calcyclin in human tissues was studied using polyclonal antibodies against this protein. In all organs examined (breast, heart, intestine, kidney, liver, ovary, placenta, stomach, thymus, and uterus) only epithelial cells and fibroblasts were stained. This suggests that calcyclin expression is related either to proliferation rate or secretion activity. The data show that calcyclin might be considered as a marker of some human epithelial cells and fibroblasts.

Calcium-Binding Proteins↗

Characterization of the cell-cycle-regulated protein calcyclin from Ehrlich ascites tumor cells. Identification of two binding proteins obtained by Ca2(+)-dependent affinity chromatography.

The nearly complete amino acid sequence obtained for murine calcyclin from Ehrlich ascites tumor cells reveals a very strong similarity with the rat and human sequences previously deduced from corresponding cDNA clones. While mouse and rat calcyclins are identical, the human protein shows at three positions a conservative amino acid replacement. Using a mouse calcyclin affinity matrix, two proteins with molecular masses of about 36 kDa have been purified from Ehrlich ascites tumor cells. The interaction between these two proteins and the immobilized calcyclin is strictly Ca2(+)-dependent. Immunological criteria and partial sequence data identify the two calcyclin-binding proteins as the phospholipid-binding protein annexin II (p36) and the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase. These observations suggest that calcyclin may exert its physiological function by a Ca2(+)-dependent interaction with cellular targets, e.g. annexin II or glyceraldehyde-3-phosphate dehydrogenase.

Amino Acid Sequence↗

Calcyclin is a calcium and zinc binding protein.

Calcyclin, a cell cycle regulated protein, was recently purified from Ehrlich ascites tumour (EAT) cells and shown to be a calcium binding protein. Here we show that calcyclin monomer and dimer also bind zinc ions. Zinc binding sites seem to be different from calcium binding sites since: preincubation with Ca2+ lacks effect on the binding of Zn2+, and Ca2+ (but not Zn2+) increases tyrosine fluorescence intensity. Binding of Zn2+ reduces the extent of the conformational changes induced by Ca2+, and seems to affect Ca2(+)-binding. The data suggest that Ca2+ and Zn2+ might trigger the biological activity of calcyclin.

Animals↗

Calcium-binding protein from mouse Ehrlich ascites-tumour cells is homologous to human calcyclin.

A Ca2+-binding protein was purified from mouse Ehrlich ascites-tumour cells. The protein forms monomers and disulphide-linked dimers, which can be separated by reverse-phase h.p.l.c. A partial amino acid sequence analysis demonstrated that the protein has an EF-hand structure. A striking homology was found to rat and human calcyclin (a member of the S-100 protein family), which is possibly involved in cell-cycle regulation.

Amino Acid Sequence↗

Tissue specific distribution of calcyclin--10.5 kDa Ca2+-binding protein.

Expression of calcyclin in different cell lines and mouse tissues was determined with polyclonal antibodies raised against calcyclin from Ehrlich ascites tumour (EAT) cells. The protein was detected in mouse skeletal and cardiac muscle, in lung, kidney and spleen, and was especially enriched in mouse smooth muscle as well as in rat fibroblasts. No positive immunological reaction was detected in mouse brain, liver and intestine and some tumourigenic cell lines. The level of calcyclin mRNA found in different cells and tissues corresponded well to the calcyclin level estimated by immunoblotting. The calcyclin-like protein was purified from mouse stomach and appeared to be very similar to the EAT protein.

Animals↗

Purification of myosin from Ehrlich ascites tumour cells (phosphorylation of its light chain and heavy chain).

1. The myosin molecule from Ehrlich ascites tumour cells consists of heavy chains of about 200 kDa and three species of light chains of 20, 19 and 15 kDa. 2. The heavy chain can be phosphorylated in vitro either by endogenous Ca2+-independent kinase or by casein kinase II. 3. The 20 and 19 kDa light chains can be phosphorylated either by an endogenous kinase or by myosin light chain kinase from chicken gizzard. 4. The Ca2+-ATPase activity of the purified myosin was 0.3 mumol/min mg protein. The Mg2+-ATPase activity was activated 14-fold by actin upon the light chain phosphorylation.

Animals↗

Purification and properties of a novel Ca2+-binding protein (10.5 kDa) from Ehrlich-ascites-tumour cells.

A novel Ca2+-binding protein (CaBP) was identified in Ehrlich-ascites-tumour cells and purified to homogeneity. The molecular mass of this protein is about 10.5 kDa as estimated by polyacrylamide-gel electrophoresis in the presence of SDS. CaBP has two Ca2+-binding sites that bind Ca2+ with a dissociation constant of about 3 x 10(-6)M. Ca2+ binding to CaBP decreases its electrophoretic mobility in urea/polyacrylamide gels, changes its u.v. spectrum, increases the intrinsic tyrosine fluorescence intensity and strengthens hydrophobic interaction with the phenyl-Sepharose matrix.

Amino Acids↗

Phosphorylation of myosin in non-muscle and smooth muscle cells. Possible rules and evolutionary trends.

Reversible phosphorylation of myosin subunits is observed in almost all eukaryotic cells. The data concerning sites and effects of phosphorylation on actin-activated ATPase activity of myosin and on its filament formation are described. These observations are discussed in terms of possible evolutionary trends and rules which may govern the process of myosin phosphorylation.

Adenosine Triphosphatases↗

[Not Available].

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Academies and Institutes↗