Search

Transforming growth factor-β (TGF-β) regulates many aspects of cellular function. A member of the mitogen-activated protein kinase kinase kinase (MAPKKK) family, TAK1, was previously identified as a mediator in the signaling pathway of TGF-β superfamily members. The yeast two-hybrid system has now revealed two human proteins, termed TAB1 and TAB2 (for TAK1 binding protein), that interact with TAK1. TAB1 and TAK1 were co-immunoprecipitated from mammalian cells. Overproduction of TAB1 enhanced activity of the plasminogen activator inhibitor 1 gene promoter, which is regulated by TGF-β, and increased the kinase activity of TAK1. TAB1 may function as an activator of the TAK1 MAPKKK in TGF-β signal transduction., The mitogen-activated protein kinase (MAPK) pathway is a conserved eukaryotic signaling module that converts receptor signals into various outputs. This pathway includes three protein kineses: MAPKKK, MAPKK, and MAPK; MAPK [...]

The mitogen-activated protein kinase (MAPK) pathway is a conserved eukaryotic signaling module that converts receptor signals into various outputs. MAPK is activated through phosphorylation by MAPK kinase (MAPKK), which is first activated by MAPKK kinase (MAPKKK). A genetic selection based on a MAPK pathway in yeast was used to identify a mouse protein kinase (TAK1) distinct from other members of the MAPKKK family. TAK1 was shown to participate in regulation of transcription by transforming growth factor-o (TGF-β). Furthermore, kinase activity of TAK1 was stimulated in response to TGF-P and bone morphogenetic protein. These results suggest that TAK1 functions as a mediator in the signaling pathway of TGF-β superfamily members., Activation of MAPKs after ligand binding to various receptors has been correlated with numerous cellular responses, including proliferation, differentiation, and regulation of specific metabolic pathways in differentiated cell types. The [...]

We have developed a method for temporal and regional gene expression targeting (TARGET) in Drosophila and show the simultaneous spatial and temporal rescue of a memory defect. The transient expression of the rutabagaencoded adenylyl cyclase in the mushroom bodies of the adult brain was necessary and sufficient to rescue the rutabaga memory deficit, which rules out a developmental brain defect in the etiology of this deficit and demonstrates an acute role for rutabaga in memory formation in these neurons. The TARGET system offers general utility in simultaneously addressing issues of when and where gene products are required. [ABSTRACT FROM AUTHOR]