Isolation and characterization of PKC-L, a new member of the protein kinase C-related gene family specifically expressed in lung, skin, and heart

1991 ◽  
Vol 11 (1) ◽  
pp. 126-133 ◽  
Author(s):  
N Bacher ◽  
Y Zisman ◽  
E Berent ◽  
E Livneh
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Gene Family ◽  
Phorbol Esters ◽  
Structural Features ◽  
Cos Cells ◽  
Isolation And Characterization ◽  
Kinase C ◽  
Human Epidermoid Carcinoma

We have isolated and characterized a new human cDNA, coding for a protein kinase, related to the protein kinase C (PKC) gene family. Although this protein kinase shares some homologous sequences and structural features with the four members of the PKC family initially isolated (alpha, beta I, beta II, and gamma), it shows more homology with the recently described PKC-related subfamily, encoded by the cDNAs delta, epsilon, and zeta. The transcript for this gene product, termed PKC-L, is most abundant in lung tissue, less expressed in heart and skin tissue, and exhibited very low expression in brain tissue. Thus, its tissue distribution is different from that described for other mammalian members of the PKC gene family, their expression being enriched in brain tissues. PKC-L is also expressed in several human cell lines, including the human epidermoid carcinoma line A431. The ability of phorbol esters to bind to and stimulate the kinase activity of PKC-L was revealed by introducing the cDNA into COS cells.

scholarly journals Isolation and characterization of PKC-L, a new member of the protein kinase C-related gene family specifically expressed in lung, skin, and heart.

1991 ◽  
Vol 11 (1) ◽  
pp. 126-133 ◽  
Author(s):  
N Bacher ◽  
Y Zisman ◽  
E Berent ◽  
E Livneh
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Gene Family ◽  
Phorbol Esters ◽  
Structural Features ◽  
Cos Cells ◽  
Isolation And Characterization ◽  
Kinase C ◽  
Human Epidermoid Carcinoma

We have isolated and characterized a new human cDNA, coding for a protein kinase, related to the protein kinase C (PKC) gene family. Although this protein kinase shares some homologous sequences and structural features with the four members of the PKC family initially isolated (alpha, beta I, beta II, and gamma), it shows more homology with the recently described PKC-related subfamily, encoded by the cDNAs delta, epsilon, and zeta. The transcript for this gene product, termed PKC-L, is most abundant in lung tissue, less expressed in heart and skin tissue, and exhibited very low expression in brain tissue. Thus, its tissue distribution is different from that described for other mammalian members of the PKC gene family, their expression being enriched in brain tissues. PKC-L is also expressed in several human cell lines, including the human epidermoid carcinoma line A431. The ability of phorbol esters to bind to and stimulate the kinase activity of PKC-L was revealed by introducing the cDNA into COS cells.

scholarly journals Isolation and characterization of protein kinase C from Y-1 adrenal cell cytoskeleton.

1989 ◽  
Vol 108 (2) ◽  
pp. 553-567 ◽  
Author(s):  
V Papadopoulos ◽  
P F Hall
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Phorbol Esters ◽  
Intact Cells ◽  
Adrenal Cells ◽  
Isolation And Characterization ◽  
Kinase C

The cytoskeletons of Y-1 mouse adrenal tumor cells contain a calcium and phospholipid-dependent protein kinase (protein kinase C) that is bound sufficiently tight to resist extraction by 0.5% Triton but not by 1.0% Triton. The enzyme has been purified to near homogeneity from cytoskeleton and cytosol. It shows features typical of this type of kinase, namely a requirement for Ca2+ and phospholipid, stimulation by tumor promoters but not by nontumor-promoting phorbol esters, and inhibition by trifluoperazine. The enzyme shows specificity for four substrates found in the cytoskeleton, namely 80, 33, 20, and 18 kD. The first three substrates are phosphorylated by the enzyme; the fourth is dephosphorylated and is therefore affected by the kinase indirectly. The 80-kD protein is the kinase enzyme itself which is autophosphorylated in vitro and in the cytoskeleton. The 20-kD protein is myosin light chain. The 33- and 18-kD proteins are unidentified. The same substrates were phosphorylated when Y-1 cells were permeabilized with digitonin and incubated with [gamma-32P]ATP and phorbol-12-myristate-13-acetate. Partly purified protein kinase C changes the extent of phosphorylation of the same substrates when added to cytoskeletons previously extracted to remove endogenous protein kinase C. Addition of Ca2+, phosphatidylserine, and phorbol-12-myristate-13-acetate to cytoskeletons, and addition of these three agents plus protein kinase C to extracted cytoskeletons, causes these structures to undergo a rapid and extensive rounding. A similar change is induced in intact cells by addition of phorbol ester. It is concluded that protein kinase C is capable of changing the shape of adrenal cells by an action that involves autophosphorylation and phosphorylation of myosin light chain. This response may in turn be related to the steroidogenic responses to ACTH and cyclic AMP.

scholarly journals The protein kinase C-related PKC-L(eta) gene product is localized in the cell nucleus.

1992 ◽  
Vol 12 (3) ◽  
pp. 1304-1311 ◽  
Author(s):  
H Greif ◽  
J Ben-Chaim ◽  
T Shimon ◽  
E Bechor ◽  
H Eldar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Nucleus ◽  
Molecular Mechanisms ◽  
Phorbol Esters ◽  
Subcellular Fractionation ◽  
Related Family ◽  
Kinase C ◽  
Human Epidermoid Carcinoma

The tumor promoters phorbol esters are thought to induce changes in cell growth and gene expression by direct activation of protein kinase C (PKC). However, the molecular mechanisms by which PKC molecules transduce signals into the cell nucleus are unknown. In this study, we provide evidence for a direct target for phorbol esters in the nucleus. We demonstrate that the new PKC-related family member, PKC-L, recently isolated by us, is expressed specifically in the cell nucleus. Localization of PKC-L in the cell nucleus is shown both by immunofluorescence staining and by subcellular fractionation experiments of several human cell lines, including the human epidermoid carcinoma line A431. Treatment of these cells by phorbol esters does not induce the down-regulation of PKC-L, in contrast to their effect on classical PKC family members. This is the only PKC isoenzyme described so far that resides permanently and specifically in the cell nucleus. PKC-L may function as an important link in tumor promoting, e.g., as a nuclear regulator of gene expression that changes the phosphorylation state of transcriptional components such as the AP-1 complex.

Isolation and characterization of two new Drosophila protein kinase C genes, including one specifically expressed in photoreceptor cells

Cell ◽  
1989 ◽  
Vol 57 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Eric Schaeffer ◽  
Dean Smith ◽  
Graeme Mardon ◽  
William Quinn ◽  
Charles Zuker
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Photoreceptor Cells ◽  
Isolation And Characterization ◽  
Kinase C ◽  
Drosophila Protein

scholarly journals A growth factor-repressible gene associated with protein kinase C-mediated inhibition of adipocyte differentiation.

1988 ◽  
Vol 107 (1) ◽  
pp. 279-286 ◽  
Author(s):  
M Navre ◽  
G M Ringold
Keyword(s):  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Phorbol Esters ◽  
Adipocyte Differentiation ◽  
Fibroblast Growth ◽  
Kinase C

The conversion of determined adipoblasts to fully differentiated adipocytes requires appropriate environmental conditions. A strict dependence on cell confluence and a facilitation by glucocorticoid hormones have previously been described. We have found that agents that are capable of activating protein kinase C, such as basic fibroblast growth factor and phorbol esters, inhibit the differentiation of the adipogenic cell line TA1 without stimulating cell growth. Here we describe the sequence and characterization of a cDNA (clone 5) that detects an RNA, the expression of which is enhanced by glucocorticoids and increasing cell density. In contrast, activators of protein kinase C including basic fibroblast growth factor, phorbol esters, and synthetic diacylglycerols inhibit clone 5 gene expression. It appears that clone 5 expression is closely linked to environmental and hormonal factors that promote the differentiation of adipogenic cells.

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