Expression of the Subunits of Protein Kinase CK2 During Oogenesis in Xenopus laevis

Abstract

Northern‐blot analysis of RNAs from different tissues demonstrated that the mRNA for the protein kinase CK2α subunit is very abundant in the ovary of Xenopus laevis. The competitive reverse‐PCR technique has been used to quantitate the mRNA for both CK2α and CK2β subunits during oogenesis. The results obtained using eight different animals consistently show an increment of 2–3‐fold in the mRNA for both subunits in vitellogenic oocytes (stages II‐VI). Each stage‐VI oocyte contains approximately 5 × 10−7 molecules CK2α mRNA and 1 × 10−7 molecules CK2β mRNA. These amounts are considerably higher than many other mRNAs analyzed in these cells. Activity measurements of CK2 using casein or a specific model peptide revealed increments of about 10–12‐fold during oogenesis, and also indicated that the amount of enzyme in the nucleus accounted for 15–30% of the total enzyme in the oocyte at all stages. Western‐blot analysis of CK2α indicated that the amount of this protein subunit also increased during oogenesis in a parallel fashion with the increment of enzymic activity.

Developmental expression patterns of candidate cofactors for vertebrate six family transcription factors

“…Previous studies demonstrate that Xenopus CKIIβ is expressed maternally (Wilhelm et al, 1995) and in the animal hemispheres at cleavage and blastula stages (Dominguez et al, 2004) (Table 2). We detected its mRNA throughout the gastrula ectoderm (Fig.…”

“… AH, adenohypophyseal placode; Ant, anterior; BA, branchial arches; BZ, border zone; C, cleavage; CG, cement gland; D. epi, dorsal epidermis; dlp, dorso-lateral placode; E, early; ecto, ectoderm; Fb, forebrain; Hb, hindbrain; lat, lateral; IX/Xg, hypoglossal/vagal ganglion; L, late; Mb, midbrain; meso, mesoderm; ms, muscle; NC, neural crest; ND, not detected; NP, neural plate; NT, neural tube; O, oocyte; Olf, olfactory placode; Oto, otocyst; PPE, pre-placodal ectoderm; Vg, trigeminal ganglion; VII/VIIIg, facial/acouticovestibular ganglion; Vp, trigeminal placode. * Data in part from Choudhury et al, 1997; David et al, 2001; de la Calle-Mustienes et al, 2002; Dominguez et al, 2004; Kriebel et al, 2007; Molenaar et al, 2000; Patterson and Krieg, 1999; Schlosser and Ahrens, 2004; Schlosser, 2006; Wilhelm et al 1995, and in part from our observations. …”

“… * Data in part from Choudhury et al, 1997; David et al, 2001; de la Calle-Mustienes et al, 2002; Dominguez et al, 2004; Kriebel et al, 2007; Molenaar et al, 2000; Patterson and Krieg, 1999; Schlosser and Ahrens, 2004; Schlosser, 2006; Wilhelm et al 1995, and in part from our observations. …”

Biochemical and Functional Characterization of Protein Kinase CK2 in Ascidian Ciona intestinalis Oocytes at Fertilization

“…In Xenopus oocyte nuclei, CK2 is probably the major phosphorylating protein, and its activity can be enhanced by polyamines (spermine or spermidine) and inhibited by heparin (20,21). Besides, in the ovary of Xenopus, the mRNA amount for both the CK2-␣ and -␤ subunits is higher than many other mRNAs and increased during oogenesis, in parallel with the increment of enzymatic activity (22). In Rana temporaria during oocyte maturation, CK2 activity increases 7 h after progesterone administration and at the final stage of maturation, suggesting that CK2 participates in the translation control mechanisms during maturation of frog oocytes (23).…”

An inactive mutant of the α subunit of protein kinase CK2 that traps the regulatory CK2β subunit

“…These latter proteins were purified by passing the supernatant fraction of bacterial extracts through a 3 ml nickel-chelate NTA-agarose column, previously equilibrated with buffer A (50 mM Tris-HCl pH 8, 20 mM P-mercaptoethanol, 100 mM NaCl, 1 mM phenylmethylsulfonyl fluoride), washed with the same buffer and eluted with a linear gradient, 10-200 mM imidazole in buffer A with 10% glycerol. The elution of CK2oc was checked by activity and SDS-gel electrophoresis while the elution of the inactive CK2aA 156 was followed by electrophoresis and Western blot using a polyclonal antibody specific for CK2a [27]. The purified preparations of CK2a and a' used had a specific activity of 67 and 42, nmol 32 P incorporated into casein/min per mg, respectively.…”