The promoter for intestinal cell kinase is head-to-head with F-Box 9 and contains functional sites for TCF7L2 and FOXA factors.

Background: Intestinal cell kinase (ICK; GeneID 22858) is a conserved MAPK and CDK-like kinase that is widely expressed in human tissues. Data from the Cancer Genome Anatomy Project indicated ICK mRNA is increased in cancer, and that its expression correlated with expression of mRNA for an uncharacterized F-box protein, FBX9 (GeneID: 26268). ICK and FBX9 genes are arranged head-to-head on opposite strands, with start sites for transcription separated by approximately 3.

Activating mutations in TOR are in similar structures as oncogenic mutations in PI3KCalpha.

TOR (Target of Rapamycin) is a highly conserved Ser/Thr kinase and a central controller of cell growth. Using the crystal structure of the related lipid kinase PI3KCgamma, we built a model of the catalytic region of TOR, from the FAT domain to near the end of the FATC domain. The model reveals that activating mutations in TOR, identified in yeast in a genetic selection for Rheb-independence, correspond to hotspots for oncogenic mutations in PI3KCalpha.

The Vam6 GEF controls TORC1 by activating the EGO complex.

The target of rapamycin complex 1 (TORC1) is a central regulator of eukaryotic cell growth that is activated by a variety of hormones (e.g., insulin) and nutrients (e.

Intestinal cell kinase, a MAP kinase-related kinase, regulates proliferation and G1 cell cycle progression of intestinal epithelial cells.

Intestinal cell kinase (ICK), originally cloned from the intestine and expressed in the intestinal crypt epithelium, is a highly conserved serine/threonine protein kinase that is similar to mitogen-activated protein kinases (MAPKs) in the catalytic domain and requires dual phosphorylation within a MAPK-like TDY motif for full activation. Despite these similarities to MAPKs, the biological functions of ICK remain unknown. In this study, we report that suppression of ICK expression in cultured intestinal epithelial cells by short hairpin RNA (shRNA) interference significantly impaired cellular proliferation and induced features of gene expression characteristic of colonic or enterocytic differentiation.

Mammalian target of rapamycin complex 1 (mTORC1) activity is associated with phosphorylation of raptor by mTOR.

mTORC1 contains multiple proteins and plays a central role in cell growth and metabolism. Raptor (regulatory-associated protein of mammalian target of rapamycin (mTOR)), a constitutively binding protein of mTORC1, is essential for mTORC1 activity and critical for the regulation of mTORC1 activity in response to insulin signaling and nutrient and energy sufficiency. Herein we demonstrate that mTOR phosphorylates raptor in vitro and in vivo.

TOR1 and TOR2 have distinct locations in live cells.

TOR is a structurally and functionally conserved Ser/Thr kinase found in two multiprotein complexes that regulate many cellular processes to control cell growth. Although extensively studied, the localization of TOR is still ambiguous, possibly because endogenous TOR in live cells has not been examined. Here, we examined the localization of green fluorescent protein (GFP) tagged, endogenous TOR1 and TOR2 in live S.

Inhibition of tristetraprolin deadenylation by poly(A) binding protein.

Tristetraprolin (TTP) is the prototype for a family of RNA binding proteins that bind the tumor necrosis factor (TNF) messenger RNA AU-rich element (ARE), causing deadenylation of the TNF poly(A) tail, RNA decay, and silencing of TNF protein production. Using mass spectrometry sequencing we identified poly(A) binding proteins-1 and -4 (PABP1 and PABP4) in high abundance and good protein coverage from TTP immunoprecipitates. PABP1 significantly enhanced TNF ARE binding by RNA EMSA and prevented TTP-initiated deadenylation in an in vitro macrophage assay of TNF poly(A) stability.

MAP kinase: it's been longer than fifteen minutes.

The review highlights evidence for different functions in the cell cycle of the two MAP kinase kinases, MEK1 and MEK2, and the two MAP kinases, ERK1 and ERK2. Functional differences may explain why instances of cell cycle arrest can be MEK1 or MEK2 dependent.

MNK kinases regulate multiple TLR pathways and innate proinflammatory cytokines in macrophages.

The MNK kinases are downstream of both the p38 and ERK MAP kinase pathways and act to increase gene expression. MNK inhibition using the compound CGP57380 has recently been reported to inhibit tumor necrosis factor (TNF) production in macrophage cell lines stimulated with Escherichia coli lipopolysaccharide (LPS). However, the range of receptors that signal through the MNK kinases and the extent of the resultant cytokine response are not known.

Loss of MNK function sensitizes fibroblasts to serum-withdrawal induced apoptosis.

Map kinase-interacting protein kinases 1 and 2 (MNK1, MNK2) function downstream of p38 and ERK MAP kinases, but there are large gaps in our knowledge of how MNKs are regulated and function. Mice deleted of both genes are apparently normal, suggesting that MNKs function in adaptive pathways during stress. Here, we show that mouse embryo fibroblasts (MEFs) obtained from mnk1 (-/-)/mnk2 (-/-) as well as mnk1 (-/-) and mnk2 (-/-) mice are sensitized to caspase-3 activation upon withdrawal of serum in comparison to wild-type cells.

Golgi manganese transport is required for rapamycin signaling in Saccharomyces cerevisiae.

The Pmr1 Golgi Ca2+/Mn2+ ATPase negatively regulates target of rapamycin complex (TORC1) signaling, the rapamycin-sensitive TOR complex in Saccharomyces cerevisiae. Since pmr1 causes resistance to rapamycin and tor1 causes hypersensitivity, we looked for genetic interactions of pmr1 with tor1. Deletion of TOR1 restored two wild-type phenotypes.

MNK1 and MNK2 regulation in HER2-overexpressing breast cancer lines.

MAPK-interacting protein kinases 1 and 2 (MNK1 and MNK2) function downstream of p38 and ERK MAPK, but there are large gaps in our knowledge of how MNKs are regulated and function. As proteins activated in the HER2/Ras/Raf/ERK pathway, the MNKs are of potential interest in HER2-overexpressing cancers. We utilized a panel of breast cell lines (HCC1419, AU565, SKBR3, MCF7, and MCF10A), three of which overexpress HER2, to characterize the amounts and activation status of MNKs and other pathway enzymes (ERKs and RSKs) in these cells.

Pmr1, a Golgi Ca2+/Mn2+-ATPase, is a regulator of the target of rapamycin (TOR) signaling pathway in yeast.

The rapamycin.FKBP12 complex inhibits target of rapamycin (TOR) kinase in TORC1. We screened the yeast nonessential gene deletion collection to identify mutants that conferred rapamycin resistance, and we identified PMR1, encoding the Golgi Ca2+/Mn2+ -ATPase.

Identification of yin-yang regulators and a phosphorylation consensus for male germ cell-associated kinase (MAK)-related kinase.

MAK (male germ cell-associated protein kinase) and MRK/ICK (MAK-related kinase/intestinal cell kinase) are human homologs of Ime2p in Saccharomyces cerevisiae and of Mde3 and Pit1 in Schizosaccharomyces pombe and are similar to human cyclin-dependent kinase 2 (CDK2) and extracellular signal-regulated kinase 2 (ERK2). MAK and MRK require dual phosphorylation in a TDY motif catalyzed by an unidentified human threonine kinase and tyrosine autophosphorylation. Herein, we establish that human CDK-related kinase CCRK (cell cycle-related kinase) is an activating T157 kinase for MRK, whereas active CDK7/cyclin H/MAT1 complexes phosphorylate CDK2 but not MRK.

The MAP kinase ERK5 binds to and phosphorylates p90 RSK.

We showed previously that p90 RSK was activated in cells expressing an activated mutant of MEK5, the activator of the MAP kinase ERK5. Based on the following evidence, we suggest that ERK5 can directly activate RSK in cells. ERK5 binds to RSK in vitro and co-immunoprecipitates from cell extracts; activation of ERK5 weakens its binding to RSK, suggesting that RSK is released upon activation.

Activation of a nuclear Cdc2-related kinase within a mitogen-activated protein kinase-like TDY motif by autophosphorylation and cyclin-dependent protein kinase-activating kinase.

Male germ cell-associated kinase (MAK) and intestinal cell kinase (ICK) are nuclear Cdc2-related kinases with nearly identical N-terminal catalytic domains and more divergent C-terminal noncatalytic domains. The catalytic domain is also related to mitogen-activated protein kinases (MAPKs) and contains a corresponding TDY motif. Nuclear localization of ICK requires subdomain XI and interactions of the conserved Arg-272, but not kinase activity or, surprisingly, any of the noncatalytic domain.

Glucose regulates interleukin-8 production in aortic endothelial cells through activation of the p38 mitogen-activated protein kinase pathway in diabetes.

We have shown that chronic elevated glucose (25 mm) increases monocyte adhesion to human aortic endothelial cells (EC). This increased adhesion is mediated primarily through induction of interleukin (IL)-8 via activation of the transcription factor AP-1 (Srinivasan, S., Yeh, M.

MAPKAP kinase 2 phosphorylates tristetraprolin on in vivo sites including Ser178, a site required for 14-3-3 binding.

MAPKAP kinase 2 (MK2) is required for tumor necrosis factor synthesis. Tristetraprolin (TTP) binds to the 3'-untranslated region of tumor necrosis factor mRNA and regulates its fate. We identified in vitro and in vivo phosphorylation sites in TTP using nanoflow high pressure liquid chromatography microelectrospray ionization tandem mass spectrometry and novel methods for direct digestion of TTP bound to affinity matrices (GSH-beads or anti-Myc linked to magnetic beads).

Methylpyridinium (MPP(+))- and nerve growth factor-induced changes in pro- and anti-apoptotic signaling pathways in SH-SY5Y neuroblastoma cells.

The parkinsonian neurotoxin methylpyridinium (MPP(+)) mimics the neuropathology of Parkinson's disease (PD) and likely kills neurons by inhibiting complex I of the electron transport chain and increasing oxidative stress. We examined the time course of activation/inactivation of multiple pro- and anti-apoptotic signaling pathways in MPP(+)-induced apoptotic death of SH-SY5Y neuroblastoma cells. We found an early increase and later decrease of transcriptional activity of the generally anti-apoptotic nuclear factor kappa-beta (NF-kappa B) and early increases in activating phosphorylation of the anti-apoptotic upstream kinase protein kinase B (PKB, also known as AKT).

Characterization of the p90 ribosomal S6 kinase 2 carboxyl-terminal domain as a protein kinase.

The carboxyl-terminal domain (CTD) of the p90 ribosomal S6 kinases (RSKs) is an important regulatory domain in RSK and a model for kinase regulation of FXXFXF(Y) motifs in AGC kinases. Its properties had not been studied. We reconstituted activation of the CTD in Escherichia coli by co-expression with active ERK2 mitogen-activated protein kinase (MAPK).