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001-es BibID:	BIBFORM039234
035-os BibID:	PMID:9268359
Első szerző:	Ács Péter
Cím:	The catalytic domain of protein kinase C chimeras modulates the affinity and targeting of phorbol ester-induced translocation / Péter Ács, Krisztina Bögi, Patricia S. Lorenzo, Adriana M. Marquez, Tamás Bíró, Zoltán Szállási, Peter M. Blumberg
Dátum:	1997
ISSN:	0021-9258
Megjegyzések:	Abstract Emerging evidence suggests important differences among protein kinase C (PKC) isozymes in terms of their regulation and biological functions. PKC is regulated by multiple interdependent mechanisms, including enzymatic activation, translocation of the enzyme in response to activation, phosphorylation, and proteolysis. As part of our ongoing studies to define the factors contributing to the specificity of PKC isozymes, we prepared chimeras between the catalytic and regulatory domains of PKCalpha, -delta, and -epsilon. These chimeras, which preserve the overall structure of the native PKC enzymes, were stably expressed in NIH 3T3 fibroblasts. Their intracellular distribution was similar to that of the endogenous enzymes, and they responded with translocation upon treatment with phorbol 12-myristate 13-acetate (PMA). We found that the potency of PMA for translocation of the PKCalpha/x chimeras from the soluble fraction was influenced by the catalytic domain. The ED50 for translocation of PKCalpha/alpha was 26 nM, in marked contrast to the ED50 of 0.9 nM in the case of the PKCalpha/epsilon chimera. In addition to this increase in potency, the site of translocation was also changed; the PKCalpha/epsilon chimera translocated mainly into the cytoskeletal fraction. PKCx/epsilon chimeras displayed twin isoforms with different mobilities on Western blots. PMA treatment increased the proportion of the higher mobility isoform. The two PKCx/epsilon isoforms differed in their localization; moreover, their localization pattern depended on the regulatory domain. Our results emphasize the complex contributions of the regulatory and catalytic domains to the overall behavior of PKC.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban külföldön készült közlemény
Megjelenés:	Journal of Biological Chemistry. - 272 : 35 (1997), p. 22148-22153. -
További szerzők:	Bögi Krisztina Lorenzo, Patricia S. Marquez, Adriana M. Szállási Zoltán Blumberg, Peter M. Bíró Tamás (1968-) (élettanász)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM039265
035-os BibID:	PMID:9353351
Első szerző:	Ács Péter
Cím:	Both the catalytic and regulatory domains of protein kinase C chimeras modulate the proliferative properties of NIH 3T3 cells / Péter Ács, Qiming J. Wang, Krisztina Bögi, Adriana M. Marquez, Patricia S. Lorenzo, Tamás Bíró, Zoltán Szállási, J. Frederic Mushinski, Peter M. Blumberg
Dátum:	1997
ISSN:	0021-9258
Megjegyzések:	Protein kinase C (PKC) isozymes exhibit important differences in terms of their regulation and biological functions. Not only may some PKC isoforms be active and others not for a given response, but the actions of different isoforms may even be antagonistic. In NIH 3T3 cells, for example, PKCdelta arrests cell growth whereas PKCepsilon stimulates it. To probe the contribution of the regulatory and the catalytic domains of PKC isozymes to isozyme-specific responses, we prepared chimeras between the regulatory and the catalytic domains of PKCalpha, -delta, and -epsilon. These chimeras, which preserve the overall structure of the native PKC enzymes, were stably expressed in mouse fibroblasts. A major objective was to characterize the growth properties of the cells that overexpress the various PKC constructs. Our data demonstrate that both the regulatory and the catalytic domains play roles in cell proliferation. The regulatory domain of PKCepsilon enhanced cell growth in the absence or presence of phorbol 12-myristate 13-acetate (PMA), and, in the presence of PMA, all chimeras with the PKCepsilon regulatory domain also gave rise to colonies in soft agar; the role of the catalytic domain of PKCepsilon was evident in the PMA-treated cells that overexpressed the PKC chimera containing the delta regulatory and the epsilon catalytic domains (PKCdelta/epsilon). The important contribution of the PKCepsilon catalytic domain to the growth of PKCdelta/epsilon-expressing cells was also evident in terms of a significantly increased saturation density in the presence of PMA, their formation of foci upon PMA treatment, and the induction of anchorage-independent growth. Aside from the growth-promoting effect of PKCepsilon, we have shown that most chimeras with PKCalpha and -delta regulatory domains inhibit cell growth. These results underscore the complex contributions of the regulatory and catalytic domains to the overall behavior of PKC.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban külföldön készült közlemény
Megjelenés:	Journal of Biological Chemistry. - 272 : 45 (1997), p. 28793-28799. -
További szerzők:	Wang, Qiming J. Bögi Krisztina Marquez, Adriana M. Lorenzo, Patricia S. Szállási Zoltán Mushinski, J. Frederic Blumberg, Peter M. Bíró Tamás (1968-) (élettanász)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM042105
Első szerző:	Szállási Zoltán
Cím:	Non-equivalent roles for the first and second zinc fingers of protein kinase Cdelta : effect of their mutation on phorbol ester-induced translocation in NIH 3T3 cells / Szállási Z., Bogi, K., Gohari, S., Biro, T., Acs, P., Blumberg, P. M.
Dátum:	1996
ISSN:	0021-9258
Megjegyzések:	Classical and novel protein kinase C (PKC) isozymes contain two, so-called cysteine-rich zinc finger domains that represent the binding sites for phorbol esters and the diacylglycerols. X-ray crystallographic, mutational, and modeling studies are providing detailed understanding of the interactions between the phorbol esters and individual PKC zinc fingers. In the present study, we explore the roles of the individual zinc fingers in the context of the intact enzyme. Our approach was to mutate either the first, the second, or both zinc fingers of PKC?, to express the mutated enzyme in NIH 3T3 cells, and to monitor the effect of the mutations on the dose-response curve for translocation induced by phorbol 12-myristate 13-acetate. The introduced mutations change into glycine the consensus proline in the phorbol ester binding loop of the zinc finger; in the isolated zinc finger, this mutation causes a 125-fold decrease in phorbol ester binding affinity. We observed that mutation in the first zinc finger caused almost no shift in the dose-response curve for translocation; mutation in the second zinc finger caused a 21-fold shift, whereas mutation in both zinc fingers caused a 138-fold shift. We conclude that the zinc fingers in the intact PKC are not equivalent and that the second zinc finger plays the predominant role in translocation of protein kinase C? in response to phorbol 12-myristate 13-acetate. Our findings have important implications for the understanding and design of PKC inhibitors targeted to the zinc finger domains.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban protein kinase C PKC zinc fingers
Megjelenés:	Journal Of Biological Chemistry. - 271 : 31 (1996), p. 18299-18301. -
További szerzők:	Bogi, K. Gohari, S. Bíró Tamás (1968-) (élettanász) Ács Péter Blumberg, Peter M.
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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