In vivo functional analysis of Drosophila protein kinase casein kinase 2 (CK2) beta-subunit.
Protein casein kinase 2 (CK2) is a heterotetramer composed of two catalytic (alpha) and two regulatory (beta) subunits. In Drosophila melanogaster, four genes encoding for one CK2alpha (DmCK2alpha) and three CK2beta (DmCK2beta, DmCK2beta' and DmCK2betates) subunits have been identified. Here, we have focused on the role of DmCK2beta. Evaluation of DNA complementary to RNA sequences and Western blot analysis revealed a complex pattern of DmCK2beta transcription and the existence of at least three distinct DmCK2beta isoforms in adult flies. The phenotype of the viable DmCK2beta mutation mushroom bodies undersized(P1) (DmCK2beta(mbuP1)) described in this study implicates a role for DmCK2beta in cell proliferation or cell survival during brain development. The isolation of a complete loss of function allele of DmCK2beta allowed us to assay the importance of various structural domains for the in vivo function of DmCK2beta. Expression of in vitro mutagenised DmCK2beta transgenes in a DmCK2beta null mutant background demonstrated an absolute requirement of the beta/beta dimerisation motif for CK2beta function, whereas removal of all N-terminal phosphorylation sites of DmCK2beta resulted in reduced viability. In contrast, a mutation in the predicted destruction box motif did not interfere with DmCK2beta function.
Jauch
Eike
E
Institut für Medizinische Strahlenkunde und Zellforschung, University of Würzburg, Versbacherstrasse 5, 97078 Würzburg, Germany.
Melzig
Joerg
J
Brkulj
Mario
M
Raabe
Thomas
T
D017398:Alternative Splicing; D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D001921:Brain / Q000201:enzymology / Q000254:growth & development; D047390:Casein Kinase II; D029721:Drosophila Proteins / Q000235:genetics* / Q000502:physiology; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D020043:Genes, Essential / Q000235:genetics / Q000502:physiology; D007527:Isoenzymes / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000502:physiology; D021122:Protein Subunits / Q000235:genetics / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D016335:Zinc Fingers / Q000235:genetics
D029721:Drosophila Proteins; D007527:Isoenzymes; D021122:Protein Subunits; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases