TY - JOUR
T1 - Protein kinase C chimeras
T2 - Catalytic domains of α and βII protein kinase C contain determinants for isotype-specific function
AU - Walker, Susan D.
AU - Murray, Nicole R.
AU - Burns, David J.
AU - Fields, Alan P.
PY - 1995/9/26
Y1 - 1995/9/26
N2 - Protein kinase C (PKC) is involved in the proliferation and differentiation of many cell types. In human erythroleukemia (K-562) cells, the PKC isoforms α and βII play distinct functional roles, α PKC is involved in phorbol 12-myristate 13-acetate-induced cytostasis and megakaryocytic differentiation, whereas βII PKC is required for proliferation. To identify regions within α and βII PKC that allow participation in these divergent pathways, we constructed chimeras in which the regulatory and catalytic domains of α and βII PKC were exchanged. These PKC chimeras can be stably expressed, exhibit enzymatic properties similar to native α and βII PKC in vitro, and participate in α and βII PKC isotype-specific pathways in K-562 cells. Expression of the β/α PKC chimera induces cytostasis in the same manner as overexpression of wild-type α PKC. In contrast, the α/βII PKC chimera, like wild-type βII PKC, selectively translocates to the nucleus and leads to increased phosphorlation of the nuclear envelope polypeptide lamin B in response to bryostatin-1. Therefore, the catalytic domains of α and βII PKC contain determinants important for α and βII PKC isotype function. These results suggest that the catalytic domain represents a potential target for modulating PKC isotype activity in vivo.
AB - Protein kinase C (PKC) is involved in the proliferation and differentiation of many cell types. In human erythroleukemia (K-562) cells, the PKC isoforms α and βII play distinct functional roles, α PKC is involved in phorbol 12-myristate 13-acetate-induced cytostasis and megakaryocytic differentiation, whereas βII PKC is required for proliferation. To identify regions within α and βII PKC that allow participation in these divergent pathways, we constructed chimeras in which the regulatory and catalytic domains of α and βII PKC were exchanged. These PKC chimeras can be stably expressed, exhibit enzymatic properties similar to native α and βII PKC in vitro, and participate in α and βII PKC isotype-specific pathways in K-562 cells. Expression of the β/α PKC chimera induces cytostasis in the same manner as overexpression of wild-type α PKC. In contrast, the α/βII PKC chimera, like wild-type βII PKC, selectively translocates to the nucleus and leads to increased phosphorlation of the nuclear envelope polypeptide lamin B in response to bryostatin-1. Therefore, the catalytic domains of α and βII PKC contain determinants important for α and βII PKC isotype function. These results suggest that the catalytic domain represents a potential target for modulating PKC isotype activity in vivo.
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M3 - Article
C2 - 7568092
AN - SCOPUS:0029045598
SN - 0027-8424
VL - 92
SP - 9156
EP - 9160
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 20
ER -