Mos is required for MAP kinase activation and is involved in microtubule organization during meiotic maturation in the mouse

Development ◽  
1996 ◽  
Vol 122 (3) ◽  
pp. 815-822 ◽  
Author(s):  
M.H. Verlhac ◽  
J.Z. Kubiak ◽  
M. Weber ◽  
G. Geraud ◽  
W.H. Colledge ◽  
...  
Keyword(s):  
Map Kinase ◽  
Meiotic Maturation ◽  
Microtubule Organization ◽  
Kinase Activation ◽  
Mouse Oocytes ◽  
M Phase ◽  
In The Wild ◽  
Cytostatic Factor ◽  
Map Kinase Kinase Kinase ◽  
Map Kinase Kinase

Mos is normally expressed during oocyte meiotic maturation in vertebrates. However, apart from its cytostatic factor (CSF) activity, its precise role during mouse meiosis is still unknown. First, we analyzed its role as a MAP kinase kinase kinase. Mos is synthesized concomitantly with the activation of MAP kinase in mouse oocytes. Moreover, MAP kinase is not activated during meiosis in oocytes from mos −/− mice. This result implies that Mos is necessary for MAP kinase activation in mouse oocytes. Raf-1, another MAP kinase kinase kinase, is already present in immature oocytes, but does not seem to be active when MAP kinase is activated. Moreover, the absence of MAP kinase activation in mos −/− oocytes demonstrates that Raf-1 cannot compensate for the lack of Mos. These results suggest that Raf-1 is not involved in MAP kinase activation. Second, we analyzed the organization of the microtubules and chromosomes in oocytes from mos −/− mice. We observed that during the transition between two meiotic M-phases, the microtubules and chromosomes evolve towards an interphase-like state in mos −/− oocytes, while in the control mos +/− oocytes they remain in an M-phase configuration, as in the wild type. Moreover, after spontaneous activation, the majority of mos −/− oocytes are arrested for at least 10 hours in a third meiotic M-phase where they exhibit monopolar half-spindles. These observations present the first evidence, in intact oocytes, of a role for the Mos/…/MAP kinase cascade in the control of microtubule and chromatin organization during meiosis.

Microtubule and chromatin behavior follow MAP kinase activity but not MPF activity during meiosis in mouse oocytes

Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 1017-1025 ◽  
Author(s):  
M.H. Verlhac ◽  
J.Z. Kubiak ◽  
H.J. Clarke ◽  
B. Maro
Keyword(s):  
Cell Cycle ◽  
Myelin Basic Protein ◽  
Map Kinase ◽  
Kinase Activity ◽  
Basic Protein ◽  
Chromatin Condensation ◽  
Meiotic Maturation ◽  
Protein Kinase Activity ◽  
Microtubule Organization ◽  
Kinase Activation

Oocyte meiotic maturation is triggered by different stimuli (hormones, unknown signals through cell interactions) in different species. These stimuli indirectly lead to the activation of a major cell cycle regulating activity, the maturation promoting factor (MPF). Other factors, such as the product of the proto-oncogene c-mos or enzymes of the MAP kinase family, are also involved in the process of maturation. MAP kinase activation occurs during meiotic maturation in oocytes from different species with different kinetics. The relationships between MPF activation and MAP kinase activation have been well studied in species such as clam and Xenopus. In this paper, we study the precise timing of MAP kinase activation (as measured by phosphorylation of exogenous myelin basic protein and shifts in mobility of ERK 1 and ERK 2) versus MPF activation (as measured by phosphorylation of exogenous histone H1) during mouse oocyte maturation and, in parallel, morphological events such as changes in microtubule organization and chromatin condensation. We observed that MAP kinase activation was delayed after MPF activation and that this activity persisted throughout maturation whereas MPF activity dropped between the two meiotic metaphases. After parthenogenetic activation of ovulated eggs, MAP kinase inactivation was very slow compared to MPF inactivation. During the first mitotic cell cycle, a rise in myelin basic protein kinase activity at M-phase was observed but it was not related to MAP kinase activation. Furthermore, microtubules and chromatin remained in a metaphase-like state during the complete period of maturation (including the period between the two meiotic metaphases) and a few hours after activation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals CZK3, a MAP Kinase Kinase Kinase Homolog in Cercospora zeae-maydis, Regulates Cercosporin Biosynthesis, Fungal Development, and Pathogenesis

2003 ◽  
Vol 16 (9) ◽  
pp. 760-768 ◽  
Author(s):  
Won-Bo Shim ◽  
Larry D. Dunkle
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Gray Leaf Spot ◽  
Open Reading Frame ◽  
Wild Type ◽  
Toxic Activity ◽  
Reading Frame ◽  
Cercospora Zeae Maydis ◽  
Map Kinase Kinase Kinase ◽  
Map Kinase Kinase

The fungus Cercospora zeae-maydis causes gray leaf spot of maize and produces cercosporin, a photosensitizing perylenequinone with toxic activity against a broad spectrum of organisms. However, little is known about the biosynthetic pathway or factors that regulate cercosporin production. Analysis of a cDNA subtraction library comprised of genes that are up-regulated during cercosporin synthesis revealed a sequence highly similar to mitogen-activated protein (MAP) kinases in other fungi. Sequencing and conceptual translation of the full-length genomic sequence indicated that the gene, which we designated CZK3, contains a 4,119-bp open reading frame devoid of introns and encodes a 1,373-amino acid sequence that is highly similar to Wis4, a MAP kinase kinase kinase in Schizosaccharomyces pombe. Targeted disruption of CZK3 suppressed expression of genes predicted to participate in cercosporin biosynthesis and abolished cercosporin production. The disrupted mutants grew faster on agar media than the wild type but were deficient in conidiation and elicited only small chlorotic spots on inoculated maize leaves compared with rectangular necrotic lesions incited by the wild type. Complementation of disruptants with the CZK3 open reading frame and flanking sequences restored wild-type levels of conidiation, growth rate, and virulence as well as the ability to produce cercosporin. The results suggest that cercosporin is a virulence factor in C. zeae-maydis during maize pathogenesis, but the pleiotropic effects of CZK3 disruption precluded definitive conclusions.

scholarly journals Silencing PsKPP4 , a MAP kinase kinase kinase gene, reduces pathogenicity of the stripe rust fungus

2018 ◽  
Vol 19 (12) ◽  
pp. 2590-2602 ◽  
Author(s):  
Xiaoguo Zhu ◽  
Jia Guo ◽  
Fuxin He ◽  
Yang Zhang ◽  
Chenglong Tan ◽  
...  
Keyword(s):  
Map Kinase ◽  
Stripe Rust ◽  
Rust Fungus ◽  
Kinase Gene ◽  
Stripe Rust Fungus ◽  
Map Kinase Kinase Kinase ◽  
Map Kinase Kinase

The ScFRK2 MAP kinase kinase kinase from Solanum chacoense affects pollen development and viability

Planta ◽  
2006 ◽  
Vol 225 (5) ◽  
pp. 1221-1231 ◽  
Author(s):  
Martin O’Brien ◽  
Madoka Gray-Mitsumune ◽  
Christelle Kapfer ◽  
Charles Bertrand ◽  
Daniel P. Matton
Keyword(s):  
Map Kinase ◽  
Pollen Development ◽  
Solanum Chacoense ◽  
Map Kinase Kinase Kinase ◽  
Map Kinase Kinase

Activation of p90rsk during meiotic maturation and first mitosis in mouse oocytes and eggs: MAP kinase-independent and -dependent activation

Development ◽  
1996 ◽  
Vol 122 (6) ◽  
pp. 1957-1964 ◽  
Author(s):  
P. Kalab ◽  
J.Z. Kubiak ◽  
M.H. Verlhac ◽  
W.H. Colledge ◽  
B. Maro
Keyword(s):  
Kinase Activity ◽  
Polar Body ◽  
Ribosomal Subunit ◽  
Germinal Vesicle ◽  
Maximum Level ◽  
Meiotic Maturation ◽  
S6 Kinase ◽  
Mouse Oocytes ◽  
M Phase ◽  
Second Polar Body

Mitogen-activated protein kinases (MAPK) become activated during the meiotic maturation of oocytes from many species; however, their molecular targets remain unknown. This led us to characterize the activation of the ribosomal subunit S6 kinase of Mr 82 X 10(3) - 92 X 10(3) (p90rsk; a major substrate of MAPK in somatic cells) in maturing mouse oocytes and during the first cell cycle of the mouse embryo. We assessed the phosphorylation state of p90rsk by examining the electrophoretic mobility shifts on immunoblots and measured the kinase activity of immunoprecipitated p90rsk on a S6-derived peptide. Germinal vesicle stage (GV) oocytes contained a doublet of Mr 82 × 10(3) and 84 × 10(3) with a low S6 peptide kinase activity (12% of the maximum level found in metaphase II oocytes). A band of Mr 86 × 10(3) was first observed 30 minutes after GV breakdown (GVBD) and became prominent within 2 to 3 hours. MAPK was not phosphorylated 1 hour after GVBD, when the p90rsk-specific S6 kinase activity reached 37 % of the M II level. 2 hours after GVBD, MAPK became phosphorylated and p90rsk kinase activity reached 86% of the maximum level. The p90rsk band of Mr 88 × 10(3), present in mature M II oocytes when S6 peptide kinase activity is maximum, appeared when MAPK phosphorylation was nearly complete (2.5 hours after GVBD). In activated eggs, the dephosphorylation of p90rsk to Mr 86 X 10(3) starts about 1 hour after the onset of pronuclei formation and continues very slowly until the beginning of mitosis, when the doublet of Mr 82 X 10(3) and 84 X 10(3) reappears. A role for a M-phase activated kinase (like p34cdc2) in p90rsk activation was suggested by the reappearance of the Mr 86 X 10(3) band during first mitosis and in 1-cell embryos arrested in M phase by nocodazole. The requirement of MAPK for the full activation of p90rsk during meiosis was demonstrated by the absence of the fully active Mr 88 X 10(3) band in maturing c-mos −/− oocytes, where MAPK is not activated. The inhibition of kinase activity in activated eggs by 6-DMAP after second polar body extrusion provided evidence that both MAPK- and p90rsk-specific phosphatases are activated at approximately the same time prior to pronuclei formation.

Sign in / Sign up

Export Citation Format

Share Document