Faculty Opinions recommendation of The homeodomain protein hmbx-1 maintains asymmetric gene expression in adult C. elegans olfactory neurons.

AbstractMulticellular organisms coordinate tissue specific responses to environmental information via both cell-autonomous and non-autonomous mechanisms. In addition to secreted ligands, recent reports implicated release of small RNAs in regulating gene expression across tissue boundaries. Here, we show that the conserved poly-U specific endoribonuclease ENDU-2 in C. elegans is secreted from the soma and taken-up by the germline to ensure germline immortality at elevated temperature. ENDU-2 binds to mature mRNAs and negatively regulates mRNA abundance both in the soma and the germline. While ENDU-2 promotes RNA decay in the soma directly via its endoribonuclease activity, ENDU-2 prevents misexpression of soma-specific genes in the germline and preserves germline immortality independent of its RNA-cleavage activity. In summary, our results suggest that the secreted RNase ENDU-2 regulates gene expression across tissue boundaries in response to temperature alterations and contributes to maintenance of stem cell immortality, probably via retaining a stem cell specific program of gene expression.

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The Caenorhabditis elegans odr-2 Gene Encodes a Novel Ly-6-Related Protein Required for Olfaction

Genetics ◽

10.1093/genetics/157.1.211 ◽

2001 ◽

Vol 157 (1) ◽

pp. 211-224 ◽

Cited By ~ 1

Author(s):

Joseph H Chou ◽

Cornelia I Bargmann ◽

Piali Sengupta

Keyword(s):

Caenorhabditis Elegans ◽

Motor Neurons ◽

Amino Terminus ◽

Signaling Proteins ◽

Related Protein ◽

Olfactory Neurons ◽

Unique Role ◽

C Elegans ◽

Founding Member ◽

High Concentrations

Abstract Caenorhabditis elegans odr-2 mutants are defective in the ability to chemotax to odorants that are recognized by the two AWC olfactory neurons. Like many other olfactory mutants, they retain responses to high concentrations of AWC-sensed odors; we show here that these residual responses are caused by the ability of other olfactory neurons (the AWA neurons) to be recruited at high odor concentrations. odr-2 encodes a membrane-associated protein related to the Ly-6 superfamily of GPI-linked signaling proteins and is the founding member of a C. elegans gene family with at least seven other members. Alternative splicing of odr-2 yields three predicted proteins that differ only at the extreme amino terminus. The three isoforms have different promoters, and one isoform may have a unique role in olfaction. An epitope-tagged ODR-2 protein is expressed at high levels in sensory neurons, motor neurons, and interneurons and is enriched in axons. The AWC neurons are superficially normal in their development and structure in odr-2 mutants, but their function is impaired. Our results suggest that ODR-2 may regulate AWC signaling within the neuronal network required for chemotaxis.

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A rapid and massive gene expression shift marking adolescent transition in C. elegans

Scientific Reports ◽

10.1038/srep03912 ◽

2014 ◽

Vol 4 (1) ◽

Cited By ~ 26

Author(s):

L. Basten Snoek ◽

Mark G. Sterken ◽

Rita J. M. Volkers ◽

Mirre Klatter ◽

Kobus J. Bosman ◽

...

Keyword(s):

Gene Expression ◽

C Elegans ◽

Adolescent Transition

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Hesx1 homeodomain protein represses transcription as a monomer and antagonises transactivation of specific sites as a homodimer

Journal of Molecular Endocrinology ◽

10.1677/jme.0.0280193 ◽

2002 ◽

Vol 28 (3) ◽

pp. 193-205 ◽

Cited By ~ 10

Author(s):

J Quirk ◽

P Brown

Keyword(s):

Gene Expression ◽

Dna Binding ◽

Binding Site ◽

Anterior Pituitary ◽

Homeodomain Protein ◽

Dependent Manner ◽

Gene Promoters ◽

Differentiation Markers ◽

Proximal Half ◽

Dna Binding Site

The homeobox repressor Hesx1, expressed throughout Rathke's pouch and required for normal pituitary development, has been implicated in anterior pituitary pathogenesis in man. Prolonged expression of Hesx1 delays the appearance of anterior pituitary terminal differentiation markers in mice, particularly the gonadotroph hormones. We tested if Hesx1 could modulate gonadotrophin gene expression directly, and found that Hesx1 repressed both common alpha subunit (alpha GSU) and luteinising hormone beta-subunit (LH beta) gene promoters. Repression mapped to the Pitx1 homeodomain protein transactivation site in the proximal alpha GSU promoter, but did not map to the equivalent site on LH beta. Hesx1 repression of the alpha GSU Pitx1 site was overridden by co-transfection of Pitx1. In contrast, Hesx1 antagonised Pitx1 transactivation of LH beta in a dose-dependent manner. This was due to monomeric binding of Hesx1 on alpha GSU and homodimerisation on LH beta. The homodimerisation site comprises the Pitx1 DNA binding site and a proximal binding site, and mutation of either inhibited homodimer formation. Conversion of the LH beta Pitx1 DNA binding site to an alpha GSU-type did not promote homodimer formation, arguing that Hesx1 has pronounced site selectivity. Furthermore, mutation of the proximal half of the homodimerisation site blocked Hesx1 antagonisation of Pitx1 transactivation. We conclude that Hesx1 monomers repress gene expression, and homodimers block specific transactivation sites.

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