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Differentiation‐dependent expression of cardiac δ‐CaMKII isoforms
Author(s) -
Hoch Brigitte,
Haase Hannelore,
Schulze Wolfgang,
Hagemann Dirk,
Morano Ingo,
Krause ErnstGeorg,
Karczewski Peter
Publication year - 1998
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/(sici)1097-4644(19980201)68:2<259::aid-jcb12>3.0.co;2-a
Subject(s) - myogenesis , myocyte , ryanodine receptor , gene isoform , skeletal muscle , phospholamban , cardiac muscle , biology , protein kinase a , microbiology and biotechnology , endoplasmic reticulum , kinase , endocrinology , biochemistry , gene
Despite their important role in controlling the cardiac Ca 2+ homeostasis, presence and functions of individual isoforms of the multifunctional Ca 2+ /calmodulin‐dependent protein kinase in the heart are not well studied. Here we report on expression of isoforms of the δ class in two differentiation states of the embryonic rat heart‐derived cell line H9c2 compared to adult rat heart. Reverse transcription coupled polymerase chain reaction analysis revealed specific expression patterns of four variants of the δ class (δ B , δ C , δ 4 , δ 9 ) in adult rat heart, H9c2 myoblasts, and skeletal muscle‐like H9c2 myotubes. δ C was identified as a common isoform with higher amounts in H9c2 cells and the prominent one in myoblasts. In contrast, expression of δ 9 accompanied cardiac as well as skeletal muscle differentiation. Expression of δ B , however, was representative for differentiated cardiac muscle, whereas δ 4 expression coincided with differentiation into the skeletal muscle‐like state. Our results demonstrate differentiation‐dependent isoform expression of the δ class of the multifunctional Ca 2+ /calmodulin‐dependent protein kinase of muscle. The identification of cardiac target proteins for this kinase, e.g. the α 1 ‐subunit of the L‐type Ca 2+ channel, the sarcoplasmic reticulum Ca 2+ ‐ATPase, phospholamban and the ryanodine receptor define H9c2 myoblasts as a suitable model system for further functional characterization of the identified cardiac δ isoforms. J. Cell. Biochem. 68:259–268, 1998. © 1998 Wiley‐Liss, Inc.