Dissection of the promoter region of the inositol 1,4,5-trisphosphate receptor gene, itr-1, in C. elegans: a molecular basis for cell-specific expression of IP3R isoforms11Edited by J. Karn

A bovine RAPD profile, generated by a 10-mer primer, was analysed by sequencing the major fragments. Three of four different fragments showed homologies to previously characterized mammalian sequences. One was 61–66% identical to LINE sequences and another was 78.5% identical to a human chromosome 2 sequence tagged site. The third fragment was 93.1% identical to the human type 2 inositol 1,4,5-trisphosphate receptor gene. This fragment had counterparts in white-tailed deer and reindeer; fragments of slightly different size in these species showed high sequence similarity and the size differences were due to varying numbers of dinucleotide microsatellite repeats inside the fragment. Key words : RAPD, artiodactyls, sequence similarity, microsatellites, type 2 inositol 1,4,5-trisphosphate receptor.

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Regulation of β-amyloid precursor protein and inositol 1,4,5-trisphosphate receptor gene expression during differentiation of a human neuronal cell line

Progress in Neuro-Psychopharmacology and Biological Psychiatry ◽

10.1016/s0278-5846(02)00352-4 ◽

2003 ◽

Vol 27 (3) ◽

pp. 351-363 ◽

Cited By ~ 8

Author(s):

John N. Murray ◽

Orisa J. Igwe

Keyword(s):

Gene Expression ◽

Amyloid Precursor Protein ◽

Cell Line ◽

Receptor Gene ◽

Neuronal Cell ◽

Human Neuronal Cell ◽

Inositol 1,4,5 Trisphosphate ◽

Β Amyloid ◽

Trisphosphate Receptor ◽

Receptor Gene Expression

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Regulated Disruption of Inositol 1,4,5-Trisphosphate Signaling in Caenorhabditis elegans Reveals New Functions in Feeding and Embryogenesis

Molecular Biology of the Cell ◽

10.1091/mbc.01-08-0422 ◽

2002 ◽

Vol 13 (4) ◽

pp. 1329-1337 ◽

Cited By ~ 52

Author(s):

Denise S. Walker ◽

Nicholas J.D. Gower ◽

Sung Ly ◽

Gemma L. Bradley ◽

Howard A. Baylis

Keyword(s):

Binding Domain ◽

Dominant Negative ◽

Dominant Negative Effect ◽

Animal Cells ◽

Specific Expression ◽

C Elegans ◽

Wide Range ◽

Inositol 1,4,5 Trisphosphate ◽

Negative Effect ◽

Pharyngeal Pumping

Inositol 1,4,5-trisphosphate (IP3) is an important second messenger in animal cells and is central to a wide range of cellular responses. The major intracellular activity of IP3 is to regulate release of Ca2+ from intracellular stores through IP3 receptors (IP3Rs). We describe a system for the transient disruption of IP3 signaling in the model organismCaenorhabditis elegans. The IP3 binding domain of the C. elegans IP3R, ITR-1, was expressed from heat shock-induced promoters in live animals. This results in a dominant-negative effect caused by the overexpressed IP3 binding domain acting as an IP3“sponge.” Disruption of IP3 signaling resulted in disrupted defecation, a phenotype predicted by previous genetic studies. This approach also identified two new IP3-mediated processes. First, the up-regulation of pharyngeal pumping in response to food is dependent on IP3 signaling. RNA-mediated interference studies and analysis of itr-1mutants show that this process is also IP3R dependent. Second, the tissue-specific expression of the dominant-negative construct enabled us to circumvent the sterility associated with loss of IP3 signaling through the IP3R and thus determine that IP3-mediated signaling is required for multiple steps in embryogenesis, including cytokinesis and gastrulation.

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The dissection of the upstream regulatory elements of the Inositol 1,4,5-trisphosphate receptor gene in Caenorhabditis elegans

Biochemical Society Transactions ◽

10.1042/bst028a177a ◽

2000 ◽

Vol 28 (5) ◽

pp. A177-A177

Author(s):

Nicholas J. D. Gower ◽

Gillian Temple ◽

Denise Walker ◽

Howard A. Baylis

Keyword(s):

Caenorhabditis Elegans ◽

Receptor Gene ◽

Regulatory Elements ◽

Inositol 1,4,5 Trisphosphate ◽

Trisphosphate Receptor

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Inositol 1,4,5-Trisphosphate Signaling Regulates Rhythmic Contractile Activity of Myoepithelial Sheath Cells in Caenorhabditis elegans

Molecular Biology of the Cell ◽

10.1091/mbc.e04-03-0198 ◽

2004 ◽

Vol 15 (8) ◽

pp. 3938-3949 ◽

Cited By ~ 57

Author(s):

Xiaoyan Yin ◽

Nicholas J.D. Gower ◽

Howard A. Baylis ◽

Kevin Strange

Keyword(s):

Caenorhabditis Elegans ◽

Contractile Activity ◽

Receptor Gene ◽

Tyrosine Kinase Receptor ◽

Sheath Cell ◽

Cell Contraction ◽

C Elegans ◽

Inositol 1,4,5 Trisphosphate ◽

Intracellular Ca ◽

Sheath Cells

Intercellular communication between germ cells and neighboring somatic cells is essential for reproduction. Caenorhabditis elegans oocytes are surrounded by and coupled via gap junctions to smooth muscle-like myoepithelial sheath cells. Rhythmic sheath cell contraction drives ovulation and is triggered by a factor secreted from oocytes undergoing meiotic maturation. We demonstrate for the first time that signaling through the epidermal growth factor-like ligand LIN-3 and the LET-23 tyrosine kinase receptor induces ovulatory contractions of sheath cells. Reduction-of-function mutations in the inositol 1,4,5-trisphosphate (IP3) receptor gene itr-1 and knockdown of itr-1 expression by RNA interference inhibit sheath contractile activity. itr-1 gain-of-function mutations increase the rate and force of basal contractions and induce tonic sheath contraction during ovulation. Sheath contractile activity is disrupted by RNAi of plc-3, one of six phospholipase C-encoding genes in the C. elegans genome. PLC-3 is a PLC-γ homolog and is expressed in contractile sheath cells of the proximal gonad. Maintenance of sheath contractile activity requires plasma membrane Ca2+ entry. We conclude that IP3 generated by LET-23 mediated activation of PLC-γ induces repetitive intracellular Ca2+ release that drives rhythmic sheath cell contraction. Calcium entry may function to trigger Ca2+ release via IP3 receptors and/or refill intracellular Ca2+ stores.

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