title: Involvement of the MAP kinase cascade in Xenopus mesoderm induction.
abstract: Mitogen-activated protein kinase (MAPK) is activated by MAPK kinase (MAPKK) in a variety of signaling pathways. This kinase cascade has been shown to function in cell proliferation and differentiation, but its role in early vertebrate development remains to be investigated. During early vertebrate embryogenesis, the induction and patterning of mesoderm are thought to be determined by signals from intercellular factors such as members of the fibroblast growth factor (FGF) family and members of the transforming growth factor-beta family. Here we show that the microinjection of either mRNA encoding a constitutively active mutant of MAPKK or mRNA encoding a constitutively active form of STE11, a MAPKK kinase, leads to the induction of mesoderm in ectodermal explants from Xenopus embryos. Moreover, the expression of MAPK phosphatase-1 (MKP-1, also called CL100) blocks the growth factor-stimulated mesoderm induction. Furthermore, injection of CL100 mRNA into two-cell stage embryos causes severe defects in gastrulation and posterior development. The effects induced by CL100 can be rescued by co-injection of wild-type MAPK mRNA. Thus, the MAPK cascade may play a crucial role in early vertebrate embryogenesis, especially during mesoderm induction.
authors.affiliation: Department of Genetics and Molecular Biology, Kyoto University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Gotoh
authors.forename: N
authors.initials: N
authors.lastname: Masuyama
authors.forename: A
authors.initials: A
authors.lastname: Suzuki
authors.forename: N
authors.initials: N
authors.lastname: Ueno
authors.forename: E
authors.initials: E
authors.lastname: Nishida
mesh_terms: D000818:Animals; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins; D017931:DNA Primers / Q000235:genetics; D054638:Dual Specificity Phosphatase 1; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism; D020930:MAP Kinase Kinase Kinases; D008648:Mesoderm / Q000201:enzymology; D020929:Mitogen-Activated Protein Kinase Kinases; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010749:Phosphoprotein Phosphatases; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D054645:Protein Phosphatase 1; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction; D014981:Xenopus / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D017931:DNA Primers; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020930:MAP Kinase Kinase Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D054638:Dual Specificity Phosphatase 1; D017027:Protein Tyrosine Phosphatases