Detection and Biochemistry of Cell Surface Protein Kinase

Kinzel, V.; Kübler, Dieter; Burow, E; Pyerin, Walter

doi:10.1007/978-3-642-70664-6_13

Cited by 7 publications

(4 citation statements)

References 23 publications

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“…The specificity for ATP and the selectivity for 3T6 cells indicate, that external ATP interact with specific sites on the cell surface. These sites could be enzymes or receptors (Weisman et al, 1988;Gordon, 1986;Kinzel et al, 1986;Kubler et al, 1986;Burnstock and Kennedy, 1985;Williams, 1987) Exogenous adenine nucleotides serve as substrates for cell surface nucleotidases, which catalyze their hydrolysis to adenosine. Adenosine was found to inhibit the growth of several cell lines (Henderson and Scott, 1981;Fox and Kelley, 1978;Ishii and Green, 19731, but the proliferation of 3T6 cells is not inhibited upon addition of adenosine, up to 1 mM (Weisman et al, 1988).…”

Section: Discussionmentioning

confidence: 99%

ATP‐resistant variants of transformed mouse fibroblasts

Belzer

Friedberg

1989

Journal Cellular Physiology

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Addition of ATP to cultures of transformed mouse fibroblasts, 3T6 cells, resulted in cell growth inhibition, whereas the growth of the non-transformed counterparts, 3T3 cells, was only slightly affected. The inhibition was found to be specific for adenine nucleotides, and concentration dependent. At relatively low concentrations (e.g., 1.0 mM) the effect of ATP was cytostatic, whereas at higher concentrations (e.g., 1.0 mM) a cytotoxic effect was exerted. ATP-resistant variants of 3T6 cells were selected by exposure of cultures to gradually elevated concentrations of ATP. The variants were found to resemble the non-transformed counterparts, 3T3 cells, more than the 3T6 parent cells, by the following criteria: ATP-induced alterations in the membrane potential, changes in membrane permeability, cell growth inhibition, and colony formation on soft agar. The data indicate that long exposure of the transformed cells to external ATP results in redifferentiation and reduction in their tumorigenicity.

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Section: Discussionmentioning

confidence: 99%

ATP‐resistant variants of transformed mouse fibroblasts

Belzer

Friedberg

1989

Journal Cellular Physiology

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“…Cell viability was evaluated by a number of independent criteria, as described previously [2][3][4][5].…”

Section: Figure 1 Cell-surface Protein Phosphorylation By Ecto-pkmentioning

confidence: 99%

“…Cell-surface (ecto-) protein kinase (PK) activities enable cells to phosphorylate membrane-bound substrates and suitable extracellular molecules ; these, in turn, have been shown to connect with important functions for the regulation of cellular development and cell-environment interactions [1]. Using intact cells for assaying ecto-PK activities [2][3][4][5], we found that a large range of proliferating and post-mitotic cell types carry serine\threonine ecto-PK with distinct substrate specificity, notably of the constitutively active CK2 (protein formerly known as casein kinase 2) and CK1 types [2,6], and cAMP-dependent PK [7].…”

Section: Introductionmentioning

confidence: 99%

Ecto-protein kinase substrate p120 revealed as the cell-surface-expressed nucleolar phosphoprotein Nopp140: a candidate protein for extracellular Ca2+-sensing

Kübler

2001

Biochemical Journal

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A variety of cell membrane proteins become phosphorylated in their ecto-domains by cell-surface protein kinase (ecto-PK) activities, as detected in a broad spectrum of cell types. This study reports the isolation and identification of a frequent ecto-PK substrate, ecto-p120, using HeLa cells as a model. Data from MS and further biochemical and immunochemical means identified ecto-p120 as a cell-surface homologue of human nucleolar phosphoprotein p140 (hNopp140), which belongs to the family of argyrophilic (AgNOR-stainable) proteins. The superposition of 32P-labelled ecto-nucleolar phosphoprotein p140 (ecto-Nopp140) with anti-Nopp140 immunostaining could be demonstrated in a wide range of cell lines without any exceptions, suggesting a nearly universal occurrence of cell-surface Nopp140. A previous, tentative association of ecto-p120 with the nucleoplasmic pre-mRNA-binding protein hnRNP U has thus been supplanted, since improved purification techniques have allowed unambiguous identification of this ecto-PK cell-surface substrate. Furthermore, we have shown that rapid suppression of ecto-hNopp140 phosphorylation resulted upon a rise in the free extracellular calcium, while lowering the calcium concentrations returned ecto-Nopp140 phosphorylation to the original level. It is important to note that these Ca2+-dependent effects on ecto-Nopp140 phosphorylation are not accompanied by alterations in the phosphorylation of other ecto-PK substrates. Our results indicate that, in addition to nucleolin, a further nucleolar protein, which was considered initially to be strictly intracellular, is identified as a cell-surface phosphoprotein.

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“…Another possible function of extracellular ATP is its property to serve as a substrate of ecto-proteinkinases, which have been detected on several cells of different origin [74]. Human neutrophils [37] and erythrocytes [75] also carry such an ectoenzyme on their cell surfaces.…”

Section: Effects and Target Cellsmentioning

confidence: 99%

Origin, metabolism and function of extracellular adenine nucleotides in the blood

Lüthje

1989

Klin Wochenschr

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In previous views the role of adenine nucleotides was thought to be confined to the intracellular space of the cell. However, research of the last decades has revealed that nucleotides also occur in the extracellular space. This survey deals with the sources, metabolism and the role in blood of the extracellular adenine mononucleotides ATP, ADP, AMP and the dinucleotides diadenosine tetraphosphate (Ap4A) and diadenosine triphosphate (Ap3A). The latter two are novel compounds, which have recently been discovered in human platelets. The mononucleotides originate from damaged tissues, from red blood cells during haemolysis, from activated platelets, the working muscle and from the nervous system, whereas the dinucleotides are exclusively released from stimulated platelets. Both the adenine mono- and the dinucleotides act as signal molecules on blood cells as well as on cells of the vascular wall, thereby modulating physiological processes such as platelet aggregation, histamine release from mast cells, regulation of vascular tone and white cell functions. In order to limit the signal effects of extracellular nucleotides, blood cells, plasma and the interior of the vessel walls are provided with nucleotide splitting enzymes: ATP, ADP and AMP are mainly degraded by ectoenzymes present on blood cells, endothelial and on smooth muscle cells, whereas dinucleotides are primarily metabolized by plasma enzymes. This review closes with the presentation of the clinical utility of Ap3A and Ap4A as tools for the diagnosis of platelet storage pool defects.

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Detection and Biochemistry of Cell Surface Protein Kinase

Cited by 7 publications

References 23 publications

ATP‐resistant variants of transformed mouse fibroblasts

ATP‐resistant variants of transformed mouse fibroblasts

Ecto-protein kinase substrate p120 revealed as the cell-surface-expressed nucleolar phosphoprotein Nopp140: a candidate protein for extracellular Ca2+-sensing

Origin, metabolism and function of extracellular adenine nucleotides in the blood

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