Muscarinic acetylcholine receptors regulate the dephosphorylation of eukaryotic translation elongation factor 2 in SNU-407 colon cancer cells.

Previously, we showed that muscarinic acetylcholine receptors (mAChRs) promote global protein biosynthesis in SNU-407 colon cancer cells. However, the molecular mechanisms underlying this event are poorly understood. Here, we asked whether mAChRs modulate the activity of eukaryotic translation elongation factor 2 (eEF2), which controls ribosomal translocation during the peptide elongation step.

VIG-1 is required for maintenance of genome stability in .

To explore the function of VIG-1 in , we analyzed the phenotypes of two deletion mutants: () and (). Both mutants exhibited phenotypes associated with genome instability, such as a high incidence of males (Him) and increased embryonic lethality. These phenotypes became more evident in succeeding generations, implying that the germline of accumulates DNA damage over generations.

Muscarinic acetylcholine receptors mediate eIF4B phosphorylation in SNU-407 colon cancer cells.

We have previously shown that muscarinic acetylcholine receptors (mAChRs) promote global protein biosynthesis in SNU-407 colon cancer cells. To gain insight into the molecular mechanisms underlying this event, we examined whether mAChRs regulate the phosphorylation of eIF4B (eukaryotic initiation factor 4B), an essential component of the translation machinery. When SNU-407 cells were treated with the cholinergic agonist carbachol, eIF4B was phosphorylated in a dose- and time-dependent manner.

The ERK1/2 and mTORC1 Signaling Pathways Are Involved in the Muscarinic Acetylcholine Receptor-Mediated Proliferation of SNU-407 Colon Cancer Cells.

Muscarinic acetylcholine receptors (mAChRs) regulate diverse cellular functions, including cell growth and proliferation, via multiple signaling pathways. Previously, we showed that mAChRs stimulate the MEK1/2-ERK1/2-RSK pathway in SNU-407 colon cancer cells and subsequently promote cell proliferation. In this study, we provide evidence that the PI3K-Akt-mTORC1-S6K1 pathway is activated by mAChRs in SNU-407 cells and that this pathway is associated with protein biosynthesis and cell proliferation.

The C. elegans VIG-1 and FRM-1 modulate carbachol-stimulated ERK1/2 activation in chinese hamster ovary cells expressing the muscarinic acetylcholine receptor GAR-3.

Many neurotransmitter receptors are known to interact with a variety of intracellular proteins that modulate signaling processes. In an effort to understand the molecular mechanism by which acetylcholine (ACh) signaling is modulated, we searched for proteins that interact with GAR-3, the Caenorhabditis elegans homolog of muscarinic ACh receptors. We isolated two proteins, VIG-1 and FRM-1, in a yeast two-hybrid screen of a C.

EGFR and PKC are involved in the activation of ERK1/2 and p90 RSK and the subsequent proliferation of SNU-407 colon cancer cells by muscarinic acetylcholine receptors.

We have previously shown that muscarinic acetylcholine receptors (mAChRs) enhance SNU-407 colon cancer cell proliferation via the ERK1/2 pathway. Here, we examined the signaling pathways linking mAChR stimulation to ERK1/2 activation and the subsequent proliferation of SNU-407 cells. The inhibition of the epidermal growth factor receptor (EGFR) by AG1478 or protein kinase C (PKC) by GF109203X significantly reduced carbachol-stimulated ERK1/2 activation and cell proliferation.

A possible role for FRM-1, a C. elegans FERM family protein, in embryonic development.

FRM-1 is a member of the FERM protein superfamily containing a FERM domain, which is a highly conserved protein-protein interaction module found in most eukaryotes. Although FRM-1 is thought to be involved in linking intracellular proteins to membrane proteins, the specific role for FRM-1 remains to be elucidated. In an effort to explore the biological function of FRM-1, we examined the phenotype of frm-1(tm4168) mutant worms.

Enhanced proliferation of SNU-407 human colon cancer cells by muscarinic acetylcholine receptors.

We investigated the expression of muscarinic acetylcholine receptors (mAChRs) and their possible involvement in the regulation of cell proliferation in four colon cancer cell lines (SNU-61, SNU-81, SNU-407, and SNU-1033) derived from Korean colon carcinoma patients. A ligand binding assay showed that all four cell lines expressed mAChRs. Treatment of the four cell lines with the cholinergic agonist carbachol led to the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2).

Role of 5'-UTR hairpins of the Turnip yellow mosaic virus RNA in replication and systemic movement.

Turnip yellow mosaic virus (TYMV) RNA has two hairpins in its 5' untranslated region (5'-UTR). To investigate the role of the hairpins in replication of TYMV, mutants lacking one or both of the two hairpins were constructed. The TYMV constructs were introduced into Chinese cabbage by an Agrobacterium-mediated T-DNA transfer method, called agroinfiltration.

Analysis of C. elegans VIG-1 expression.

Double-stranded RNA (dsRNA) induces gene silencing in a sequence-specific manner by a process known as RNA interference (RNAi). The RNA-induced silencing complex (RISC) is a multi-subunit ribonucleoprotein complex that plays a key role in RNAi. VIG (Vasa intronic gene) has been identified as a component of Drosophila RISC; however, the role VIG plays in regulating RNAi is poorly understood.

Regulation of ERK1/2 by the C. elegans muscarinic acetylcholine receptor GAR-3 in Chinese hamster ovary cells.

Three G-protein-linked acetylcholine receptors (GARs) exist in the nematode C. elegans. GAR-3 is pharmacologically most similar to mammalian muscarinic acetylcholine receptors (mAChRs).

Agonist-induced internalization of the Caenorhabditis elegans muscarinic acetylcholine receptor GAR-3 in Chinese hamster ovary cells.

Many membrane-bound neurotransmitter receptors are known to be internalized by exposure to agonist. This agonist-induced receptor internalization is considered to play important roles in receptor-mediated signaling. Here we investigated the internalization of GAR-3, a Caenorhabditis elegans muscarinic acetylcholine receptor, using cultured mammalian cells.

Stimulation of cyclic AMP production by the Caenorhabditis elegans muscarinic acetylcholine receptor GAR-3 in Chinese hamster ovary cells.

Among the three G-protein-linked acetylcholine receptors (GARs) in Caenorhabditis elegans (C. elegans), GAR-3 is structurally and pharmacologically most similar to mammalian muscarinic acetylcholine receptors (mAChRs). Using Chinese hamster ovary (CHO) cells stably expressing GAR-3b, the major alternatively spliced isoform of GAR-3, we observed that carbachol stimulated cyclic AMP (cAMP) production in a dose- and time-dependent manner.

Alternative splicing of the muscarinic acetylcholine receptor GAR-3 in Caenorhabditis elegans.

Among the three G-protein-linked acetylcholine (ACh) receptors (GAR-1, -2, and -3) in Caenorhabditis elegans (C. elegans), GAR-3 appears most similar to mammalian muscarinic ACh receptors (mAChRs). The gar-3 gene, unlike mammalian mAChR genes, contains introns within the coding region.