Two dual specificity kinases are preferentially induced by wild-type rather than by oncogenic RAS-P21 in Xenopus oocytes

Abstract

In prior studies, we have found that oncogenic ras-p21 protein induces oocyte maturation using pathways that differ from those activated by insulin-induced wild-type ras-p21. Both oncogenic and wild-type ras-p21 require interactions with raf, but unlike oncogenic ras-p21, insulin-activated wild-type ras-p21 does not depend completely on activation of MEK and MAP kinase (MAPK or ERK) on the raf kinase pathway. To determine what raf-dependent but MAPK-independent pathway is activated by wild-type ras-p21, we have analyzed gene expression in oocytes induced to mature either with oncogenic ras-p21 or with insulin using a newly available Xenopus gene array. We find a number of proteins that are preferentially expressed in one or the other system. Of these, two proteins, both dual function kinases, T-Cell Origin Protein Kinase (TOPK) and the nuclear kinase, DYRK1A, are preferentially expressed in the insulin system. Confirming this finding, blots of lysates of oocytes, induced to mature with oncogenic ras-p21 and insulin, with anti-TOPK and anti-DYRK1A show much higher protein expression in the lysates from the insulin-matured oocytes. Neither of these kinases activates or is activated by MAPK and is therefore an attractive candidate for being on a signal transduction pathway that is unique to insulin-activated wild-type ras-p21-induced oocyte maturation.

Phospho-Signaling at Oocyte Maturation and Fertilization: Set Up for Embryogenesis and Beyond Part I. Protein Kinases

“…During mitosis, TOPK-Thr-9 was phosphorylated by cdk1/cyclin B and TOPK significantly associates with mitotic spindles . Insulin-matured Xenopus oocytes showed much higher expression of TOPK and nuclear kinase (DYRK1A) but neither of these kinases activates or is activated by MAPK and is therefore unique to insulin-activated wild-type p21 Ras -induced oocyte maturation via the activation of Raf (Qu et al 2006;Qu et al 2007). The functions of insulin-activated wild-type p21 Ras do not depend on the two classic Raf targets, MEK and MAPK (MAPK or ERK) (Qu et al 2006;Qu et al 2007).…”

“…In nematode oocytes, DYRK2/MBK2, a member of DYRK, in cooperation with CDK1 (this kinase catalyses activating phosphorylation of MBK-2 on Ser-68) (Cheng et al 2009), GSK3, and Kin-19, phosphorylates and promotes degradation of OMA-1 that regulates oocyte-to-embryo transition (Nishi and Lin 2005;Qu et al 2006;Qu et al 2007;Stitzel et al 2007;Stitzel et al 2006). In Xenopus oocytes, Ras-dependent oocyte maturation involves the function of DYRK1A (Qu et al 2006;Qu et al 2007).…”

“…In Xenopus oocytes, Ras-dependent oocyte maturation involves the function of DYRK1A (Qu et al 2006;Qu et al 2007). …”

Phospho-Signaling at Oocyte Maturation and Fertilization: Set Up for Embryogenesis and Beyond Part II. Kinase Regulators and Substrates

“…elegans EGG-3 is a member of protein-tyrosine phosphatase-like (PTPL) family, whose mutant egg undergoes fertilization normally but has a defect in polarized dispersal of Factin, formation of chitin eggshell, and production of polar bodies (Maruyama et al 2007). Although enzymatic substrate for has not yet been demonstrated (PTPL proteins are supposed to be pseudo-phosphatase), its functional interaction with CHS-1, which is required for deposition of egg shell, plays a role for proper distribution of MBK-2 kinase that regulates degradation of maternal proteins and egg-to-embryo transition (Nishi and Lin 2005;Qu et al 2006;Qu et al 2007;Stitzel et al 2007;Stitzel et al 2006). Other members of PTPL family such as EGG-4 and EGG-5 have also been characterized as components of meiotic cell cycle progression and egg-to-embryo transition.…”

“…It should be note that active Ras increased MAPK and S6K activities and sensitized the oocytes to insulin-stimulated maturation via IRS-1 (Chuang et al 1994). T-Cell Origin protein Kinase (TOPK) and the nuclear kinase, DYRK1A are attractive candidates in insulin mediated wild-type p21 Ras -induced oocyte maturation independent of MAPK (Qu et al 2006;Qu et al 2007). Phospholipase D (PLD) activity induced MAPK and S6K II activity might constitute a relevant step in Ras-induced GVBD in Xenopus oocytes was also reported (Carnero and Lacal 1995).…”