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.

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.

scholarly journals Downregulation of c-fms gene expression in human monocytes treated with phorbol esters and colony-stimulating factor 1

Blood ◽  
1989 ◽  
Vol 74 (1) ◽  
pp. 123-129 ◽  
Author(s):  
E Sariban ◽  
K Imamura ◽  
M Sherman ◽  
V Rothwell ◽  
P Pantazis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Esters ◽  
Constitutive Expression ◽  
Human Monocytes ◽  
Colony Stimulating Factor ◽  
Protein Levels ◽  
Kinase C ◽  
Stimulating Factor

Abstract The colony-stimulating factor-1 (CSF-1) regulates survival, growth, and differentiation of monocytes by binding to a single class of high- affinity receptors. The CSF-1 receptor is identical to the product of the c-fms protooncogene. The present studies monitored the effects of TPA and CSF-1 on c-fms gene expression in human monocytes. The results demonstrate that TPA downmodulates the constitutive expression of c-fms mRNA to low but detectable levels. Treatment of human monocytes with TPA was similarly associated with decreases in levels of the 138- and 125-Kd c-fms-encoded proteins. However, the kinetics of c-fms protein downmodulation indicated independent effects of TPA on c-fms expression at the RNA and protein levels. Furthermore, c-fms protein levels subsequently recovered despite persistently low levels of c-fms mRNA. Although previous studies demonstrated that c-fms protein is down- regulated in the presence of CSF-1, the present results indicate that CSF-1 also downregulates levels of c-fms mRNA. Moreover, the results indicate that CSF-1 increases protein kinase C activity in the membrane fraction. Together, these findings suggest that c-fms gene expression is differentially regulated at both the RNA and protein levels after activation of protein kinase C in human monocytes treated with TPA and CSF-1.

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 Bryostatin 1 activates protein kinase C and induces monocytic differentiation of HL-60 cells

Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 208-213 ◽  
Author(s):  
RM Stone ◽  
E Sariban ◽  
GR Pettit ◽  
DW Kufe
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Growth Inhibition ◽  
Phorbol Ester ◽  
Phorbol Esters ◽  
Cell Protein ◽  
Monocytic Differentiation ◽  
Bryostatin 1 ◽  
Kinase C

Phorbol esters induce the human HL-60 promyelocytic cell line to differentiate along a monocytic pathway. This induction of differentiation may involve phorbol ester-induced activation of the phospholipid- and calcium-dependent protein kinase C. Bryostatin 1, a macrocyclic lactone, has been shown to compete with phorbol esters for binding to protein kinase C. We have confirmed that bryostatin 1 translocates activity of protein kinase C from the cytosolic to membrane fractions of HL-60 cells. The present results also demonstrate that bryostatin 1 (10 nmol/L) induces monocytic differentiation of HL- 60 cells as determined by adherence, growth inhibition, appearance of monocyte cell surface antigens, and alpha-naphthyl acetate esterase staining. Furthermore, bryostatin 1 (10 nmol/L) downregulated c-myc expression and induced c-fos, c-fms, and tumor necrosis factor transcripts. These changes in gene expression induced by bryostatin 1 are similar to those associated with phorbol ester-induced monocytic differentiation of HL-60 cells. In contrast, exposure to a higher concentration of bryostatin 1 (100 nmol/L) had less of an effect on growth inhibition of HL-60 cells and changes in gene expression. Moreover, 100 nmol/L bryostatin 1 antagonized the cytostatic effects and adherence induced by phorbol esters. Our results thus suggest that bryostatin 1 activates HL-60 cell protein kinase C and that this effect is associated with induction of monocytic differentiation.

Stimulation of protein kinase C pathway mediates endocytosis of human nongastric H+-K+-ATPase, ATP1AL1

2002 ◽  
Vol 283 (2) ◽  
pp. F335-F343 ◽  
Author(s):  
J. Reinhardt ◽  
M. Kosch ◽  
M. Lerner ◽  
H. Bertram ◽  
D. Lemke ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Phorbol Esters ◽  
Ion Pump ◽  
Membrane Expression ◽  
Kinase C ◽  
Plasma Membrane Expression ◽  
Functional Inactivation

The human nongastric H+-K+-ATPase, ATP1AL1, shown to reabsorb K+ in exchange for H+ or Na+, is localized in the luminal plasma membrane of renal epithelial cells. It is presumed that renal H+-K+-ATPases can be regulated by endocytosis. However, little is known about the molecular mechanisms that control plasma membrane expression of renal H+-K+-ATPases. In our study, activation of protein kinase C (PKC) using phorbol esters (phorbol 12-myristate 13-acetate) leads to clathrin-dependent internalization and intracellular accumulation of the ion pump in stably transfected Madin-Darby canine kidney cells. Functional inactivation of the H+-K+-ATPase by PKC activation is shown by intracellular pH measurements. Proton extrusion capacity of ATP1AL1-transfected cells is drastically reduced after phorbol 12-myristate 13-acetate incubation and can be prevented with the PKC blocker bisindolylmaleimide. Ion pump internalization and inactivation are specifically mediated by the PKC pathway, whereas activation of the protein kinase A pathway has no influence. Our results show that the nongastric H+-K+-ATPase is a specific target for the PKC pathway. Therefore, PKC-mediated phosphorylation is a potential regulatory mechanism for apical nongastric H+-K+-ATPase plasma membrane expression.

Activation of distinct protein kinase C isozymes by phorbol esters: correlation with induction of interleukin 1.beta. gene expression

Biochemistry ◽  
1989 ◽  
Vol 28 (8) ◽  
pp. 3569-3576 ◽  
Author(s):  
Berta Strulovici ◽  
Sarkiz Daniel-Issakani ◽  
Edwin Oto ◽  
John Nestor ◽  
Hardy Chan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Esters ◽  
Interleukin 1 ◽  
Interleukin 1 Beta ◽  
Kinase C ◽  
Beta Gene

scholarly journals Downregulation of c-fms gene expression in human monocytes treated with phorbol esters and colony-stimulating factor 1

Blood ◽  
1989 ◽  
Vol 74 (1) ◽  
pp. 123-129 ◽  
Author(s):  
E Sariban ◽  
K Imamura ◽  
M Sherman ◽  
V Rothwell ◽  
P Pantazis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Esters ◽  
Constitutive Expression ◽  
Human Monocytes ◽  
Colony Stimulating Factor ◽  
Protein Levels ◽  
Kinase C ◽  
Stimulating Factor

The colony-stimulating factor-1 (CSF-1) regulates survival, growth, and differentiation of monocytes by binding to a single class of high- affinity receptors. The CSF-1 receptor is identical to the product of the c-fms protooncogene. The present studies monitored the effects of TPA and CSF-1 on c-fms gene expression in human monocytes. The results demonstrate that TPA downmodulates the constitutive expression of c-fms mRNA to low but detectable levels. Treatment of human monocytes with TPA was similarly associated with decreases in levels of the 138- and 125-Kd c-fms-encoded proteins. However, the kinetics of c-fms protein downmodulation indicated independent effects of TPA on c-fms expression at the RNA and protein levels. Furthermore, c-fms protein levels subsequently recovered despite persistently low levels of c-fms mRNA. Although previous studies demonstrated that c-fms protein is down- regulated in the presence of CSF-1, the present results indicate that CSF-1 also downregulates levels of c-fms mRNA. Moreover, the results indicate that CSF-1 increases protein kinase C activity in the membrane fraction. Together, these findings suggest that c-fms gene expression is differentially regulated at both the RNA and protein levels after activation of protein kinase C in human monocytes treated with TPA and CSF-1.

scholarly journals Bryostatin 1 activates protein kinase C and induces monocytic differentiation of HL-60 cells

Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 208-213 ◽  
Author(s):  
RM Stone ◽  
E Sariban ◽  
GR Pettit ◽  
DW Kufe
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Growth Inhibition ◽  
Phorbol Ester ◽  
Phorbol Esters ◽  
Cell Protein ◽  
Monocytic Differentiation ◽  
Bryostatin 1 ◽  
Kinase C

Abstract Phorbol esters induce the human HL-60 promyelocytic cell line to differentiate along a monocytic pathway. This induction of differentiation may involve phorbol ester-induced activation of the phospholipid- and calcium-dependent protein kinase C. Bryostatin 1, a macrocyclic lactone, has been shown to compete with phorbol esters for binding to protein kinase C. We have confirmed that bryostatin 1 translocates activity of protein kinase C from the cytosolic to membrane fractions of HL-60 cells. The present results also demonstrate that bryostatin 1 (10 nmol/L) induces monocytic differentiation of HL- 60 cells as determined by adherence, growth inhibition, appearance of monocyte cell surface antigens, and alpha-naphthyl acetate esterase staining. Furthermore, bryostatin 1 (10 nmol/L) downregulated c-myc expression and induced c-fos, c-fms, and tumor necrosis factor transcripts. These changes in gene expression induced by bryostatin 1 are similar to those associated with phorbol ester-induced monocytic differentiation of HL-60 cells. In contrast, exposure to a higher concentration of bryostatin 1 (100 nmol/L) had less of an effect on growth inhibition of HL-60 cells and changes in gene expression. Moreover, 100 nmol/L bryostatin 1 antagonized the cytostatic effects and adherence induced by phorbol esters. Our results thus suggest that bryostatin 1 activates HL-60 cell protein kinase C and that this effect is associated with induction of monocytic differentiation.

scholarly journals Differential translocation of protein kinase C isozymes by phorbol esters, EGF, and ANG II in rat liver WB cells

1998 ◽  
Vol 274 (4) ◽  
pp. C974-C982 ◽  
Author(s):  
Judith A. Maloney ◽  
Oxana Tsygankova ◽  
Agnieszka Szot ◽  
Lijun Yang ◽  
Quiyang Li ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Rat Liver ◽  
Phorbol Esters ◽  
Subcellular Fractionation ◽  
Resting Cells ◽  
Ang Ii ◽  
Directed Movement ◽  
Kinase C ◽  
A Minor

The protein kinase C (PKC) family represents an important group of enzymes whose activation is associated with their translocation from the cytosol to different cellular membranes. In this study, the spatial distribution of PKC-α, -δ and -ε in rat liver epithelial (WB) cells has been examined by Western blot analysis after subcellular fractionation. Cytosolic, membrane, nuclear, and cytoskeletal fractions were obtained from cells stimulated with phorbol 12-myristate 13-acetate (PMA), angiotensin II (ANG II), or epidermal growth factor (EGF). PMA caused most of the PKC-α, -δ and -ε initially present in the cytosol to be transported to the membrane and nuclear fractions. In contrast, both ANG II and EGF induced only a minor translocation of PKC-α to the membrane fraction but caused a statistically significant membrane-directed movement of PKC-δ and -ε. Translocation of PKC-δ and -ε to the nucleus induced by ANG II and EGF was transient and quantitatively smaller than that induced by PMA. PKC-δ and -ε were present in the cytoskeleton of resting cells, but although PMA, ANG II, and EGF caused some changes in their content, these were variable, suggesting that the cytoskeleton fraction was heterogeneous. PKC depletion inhibited ANG II-induced mitogenesis and the sustained activation of Raf-1 and extracellular regulated protein kinase (ERK). However, although PKC depletion inhibited EGF-induced mitogenesis, the maximum EGF-induced activation of the ERK pathway was only slightly retarded. We hypothesize that PKC-δ and -ε are involved in mitogenesis via both ERK-dependent and ERK-independent mechanisms. These results support the notion that specific PKC isozymes exert spatially defined effects by virtue of their directed translocation to distinct intracellular sites.

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