High impact information on CKA2

• The alpha' subunit encoded by the CKA2 gene is 60% identical to the CKA1-encoded alpha subunit and 55% identical to the Drosophila alpha subunit (A. Saxena, R. Padmanabha, and C. V. C. Glover, Mol. Cell. Biol. 7:3409-3417, 1987) [1].
• Null mutations in the CKA1 gene do not confer a detectable phenotype (J. L.-P. Chen-Wu, R. Padmanabha, and C. V. C. Glover, Mol. Cell. Biol. 8:4981-4990, 1988), presumably because of the presence of the CKA2 gene [1].
• Haploid cells in which the CKA2 gene alone is disrupted show no detectable phenotype, but haploid cells carrying disruptions in both the CKA1 and CKA2 genes are inviable [1].
• We report here the identification of CDC37, which encodes a putative Hsp90 co-chaperone, as a multicopy suppressor of a temperature-sensitive allele (cka2-13(ts)) of the CKA2 gene encoding the alpha' catalytic subunit of protein kinase CKII [2].
• Five independent temperature-sensitive alleles of the CKA2 gene were isolated and used to analyze the function of CKII during the cell cycle [3].

Biological context of CKA2

• CKA2 and its homologue CKA1 specify catalytic subunits of protein kinase CK2 [4].
• We report here that mutations in CKA2, identified through an insertional mutagenesis screen, confer fluconazole resistance [4].
• Halogenated benzimidazole inhibitors of phosphorylation, in vitro and in vivo, of the surface acidic proteins of the yeast ribosomal 60S subunit by endogenous protein kinases CK-II and PK60S [5].

Anatomical context of CKA2

• The cka2 mutants, on the other hand, exhibited only 25 to 30% of the in vitro CS activity found in wild-type membranes, indicating that the alpha' subunit of CK2 kinase is necessary for full activation of CS [6].

Associations of CKA2 with chemical compounds

• Several clinical fluconazole-resistant isolates overexpress some Cka2p-responsive genes [4].
• In addition, both the elo3 and cka2 mutants showed increased sensitivity to the CS inhibitors australifungin and fumonisin B(1) [6].
• Ceramide/long-chain base phosphate rheostat in Saccharomyces cerevisiae: regulation of ceramide synthesis by Elo3p and Cka2p [6].
• Overexpression of ZDS1,2 suppressed the temperature sensitivity, geldanamycin (GA) sensitivity, slow growth, and flocculation of multiple cka2 alleles and enhanced CK2 activity in vivo toward a known physiological substrate, Fpr3 [7].

Other interactions of CKA2

• In addition, a mutation in CRZ1, which specifies a homologue of the Saccharomyces cerevisiae transcription factor that is a major target of calcineurin, suppresses fluconazole resistance of cka2 mutants [4].
• We suggest that a Cka2p-dependent regulatory pathway is altered by clinically derived azole resistance mutations [4].
• Two of them correspond to CK-II and the other three have been called RAP-1, RAP-II, and RAP-III [8].

References