scholarly journals CNGA3 acts as a cold sensor in hypothalamic neurons

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Viktor V Feketa ◽  
Yury A Nikolaev ◽  
Dana K Merriman ◽  
Sviatoslav N Bagriantsev ◽  
Elena O Gracheva
Keyword(s):  
Preoptic Area ◽  
Ground Squirrels ◽  
Cold Sensitivity ◽  
Neuronal Circuitry ◽  
Ictidomys Tridecemlineatus ◽  
Wide Range ◽  
Cold Sensitive ◽  
Thermoregulatory System ◽  
Cold Sensor ◽  
Thermogenic Response

Most mammals maintain their body temperature around 37°C, whereas in hibernators it can approach 0°C without triggering a thermogenic response. The remarkable plasticity of the thermoregulatory system allowed mammals to thrive in variable environmental conditions and occupy a wide range of geographical habitats, but the molecular basis of thermoregulation remains poorly understood. Here we leverage the thermoregulatory differences between mice and hibernating thirteen-lined ground squirrels (Ictidomys tridecemlineatus) to investigate the mechanism of cold sensitivity in the preoptic area (POA) of the hypothalamus, a critical thermoregulatory region. We report that, in comparison to squirrels, mice have a larger proportion of cold-sensitive neurons in the POA. We further show that mouse cold-sensitive neurons express the cyclic nucleotide-gated ion channel CNGA3, and that mouse, but not squirrel, CNGA3 is potentiated by cold. Our data reveal CNGA3 as a hypothalamic cold sensor and a molecular marker to interrogate the neuronal circuitry underlying thermoregulation.

Vasomotor thresholds in the squirrel monkey: effects of central and peripheral temperature

1980 ◽  
Vol 48 (1) ◽  
pp. 89-96 ◽  
Author(s):  
W. C. Lynch ◽  
E. R. Adair ◽  
B. W. Adams
Keyword(s):  
Linear Function ◽  
Squirrel Monkey ◽  
Preoptic Area ◽  
Squirrel Monkeys ◽  
Saimiri Sciureus ◽  
Wide Range ◽  
Thermoregulatory System ◽  
Peripheral Temperature

Six squirrel monkeys (Saimiri sciureus) participated in two ex,eriments examining how central (preoptic/anterior hypothalamic, Tpo) and peripheral (ambient, Ta, or mean skin, Tsk) temperatures influence peripheral vasomotion. In the first experiment, four monkeys with unilateral preoptic thermodes were exposed to a wide range of central (23 degrees C less than Tpo less than 44 degrees C) and peripheral (10 degrees C less than Ta less than 38 degrees C) temperatures. Results indicated that the skin of both tail and foot vasodilates at discrete but unique Ta thresholds (Tpo congruent to 39 degrees C) and that raising Tpo lowers these thresholds. In the second experiment, results from two monkeys implanted with bilateral thermodes surrounding the preoptic area replicated those of experiment 1. Subsequent tests with these two monkeys on the quantitative interaction between central and peripheral temperatures indicated that the dilation threshold is approximately a linear function of Tpo and Tsk. These effects are related to the interaction between central and peripheral inputs to the thermoregulatory system.

Suppressors of a Cold-Sensitive Mutation in Yeast U4 RNA Define Five Domains in the Splicing Factor Prp8 That Influence Spliceosome Activation

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1667-1682 ◽  
Author(s):  
Andreas N Kuhn ◽  
David A Brow
Keyword(s):  
Large Scale ◽  
Splicing Factor ◽  
Cold Sensitivity ◽  
Splicing Factors ◽  
Loss Of Function ◽  
U1 Snrnp ◽  
Snrnp Protein ◽  
Cold Sensitive ◽  
Spliceosome Activation ◽  
U4 Rna

AbstractThe highly conserved splicing factor Prp8 has been implicated in multiple stages of the splicing reaction. However, assignment of a specific function to any part of the 280-kD U5 snRNP protein has been difficult, in part because Prp8 lacks recognizable functional or structural motifs. We have used a large-scale screen for Saccharomyces cerevisiae PRP8 alleles that suppress the cold sensitivity caused by U4-cs1, a mutant U4 RNA that blocks U4/U6 unwinding, to identify with high resolution five distinct regions of PRP8 involved in the control of spliceosome activation. Genetic interactions between two of these regions reveal a potential long-range intramolecular fold. Identification of a yeast two-hybrid interaction, together with previously reported results, implicates two other regions in direct and indirect contacts to the U1 snRNP. In contrast to the suppressor mutations in PRP8, loss-of-function mutations in the genes for two other splicing factors implicated in U4/U6 unwinding, Prp44 (Brr2/Rss1/Slt22/Snu246) and Prp24, show synthetic enhancement with U4-cs1. On the basis of these results we propose a model in which allosteric changes in Prp8 initiate spliceosome activation by (1) disrupting contacts between the U1 snRNP and the U4/U6-U5 tri-snRNP and (2) orchestrating the activities of Prp44 and Prp24.

scholarly journals Odontoblast TRPC5 channels signal cold pain in teeth

2021 ◽  
Vol 7 (13) ◽  
pp. eabf5567
Author(s):  
Laura Bernal ◽  
Pamela Sotelo-Hitschfeld ◽  
Christine König ◽  
Viktor Sinica ◽  
Amanda Wyatt ◽  
...  
Keyword(s):  
Relative Sensitivity ◽  
Cellular Component ◽  
Sensory Transduction ◽  
Cold Sensation ◽  
Cold Pain ◽  
Sensing System ◽  
Cold Sensitive ◽  
Cellular Components ◽  
Cold Sensor ◽  
Cold Sensing

Teeth are composed of many tissues, covered by an inflexible and obdurate enamel. Unlike most other tissues, teeth become extremely cold sensitive when inflamed. The mechanisms of this cold sensation are not understood. Here, we clarify the molecular and cellular components of the dental cold sensing system and show that sensory transduction of cold stimuli in teeth requires odontoblasts. TRPC5 is a cold sensor in healthy teeth and, with TRPA1, is sufficient for cold sensing. The odontoblast appears as the direct site of TRPC5 cold transduction and provides a mechanism for prolonged cold sensing via TRPC5’s relative sensitivity to intracellular calcium and lack of desensitization. Our data provide concrete functional evidence that equipping odontoblasts with the cold-sensor TRPC5 expands traditional odontoblast functions and renders it a previously unknown integral cellular component of the dental cold sensing system.

Differential effects of cytokines on thermosensitive neurons in guinea pig preoptic area slices

1991 ◽  
Vol 261 (5) ◽  
pp. R1096-R1103 ◽  
Author(s):  
M. Shibata ◽  
C. M. Blatteis
Keyword(s):  
Guinea Pig ◽  
Preoptic Area ◽  
Interleukin 1 ◽  
Interleukin 1 Beta ◽  
Necrosis Factor Alpha ◽  
Firing Rates ◽  
Artificial Cerebrospinal Fluid ◽  
Cold Sensitive ◽  
Factor Alpha ◽  
Necrosis Factor

This study was undertaken to determine whether the reported different courses of the febrile responses to the cytokines interleukin-1 beta (IL-1), interferon-alpha 2 (IFN), and tumor necrosis factor-alpha (TNF) might have neuroelectrophysiological correlates. The reactions of individual thermosensitive neurons in the preoptic area (POA) were evaluated by recording their extracellular single-unit firing rates (FR) in slices of guinea pig POA perfused with artificial cerebrospinal fluid (aCSF), human recombinant IL-1 (50-500 ng), IFN (1,000-8,000 U), and TNF (400-5,000 ng) (all doses per min/ml aCSF); thermosensitivity was assessed by FR responses to changes of perfusate temperature (32-42 degrees C). Overall, these cytokines depressed the FR of warm-sensitive units and excited those of cold-sensitive units, in agreement with expectations. However, the responses of individual neurons treated with two or all three cytokines were dissimilar: 61% of the units tested reacted differentially to two or three cytokines, 32% exhibited identical responses, and 7% had no response to any cytokine. These results support the possibility that IL-1, IFN, and TNF may affect not the same but rather distinct neurons functionally connected to common pyrogenic effectors. Thus they suggest that differential neuronal substrates may be utilized by each cytokine to exert its pyrogenic effect.

Neuronal circuitry in the basal septum and preoptic area of the rat

1977 ◽  
Vol 133 (1) ◽  
pp. 95-106 ◽  
Author(s):  
C.R. Gardner ◽  
S.W. Phillips
Keyword(s):  
Preoptic Area ◽  
Neuronal Circuitry ◽  
Basal Septum

Sequential cold-sensitive mutations in Aspergillus fumigatus

1978 ◽  
Vol 24 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Ole Nielsen ◽  
Kenneth F. Gregory
Keyword(s):  
Aspergillus Fumigatus ◽  
Type A ◽  
Maximum Growth ◽  
Cold Sensitivity ◽  
Nonpermissive Temperature ◽  
Wild Type ◽  
Cold Sensitive ◽  
Wild Type Parent ◽  
Thermotolerant Fungus

Mutants of the thermotolerant fungus Aspergillus fumigatus I-21 (ATCC 32722) unable to grow at 37 °C were sought. Cold-sensitive mutants were enriched from progeny spores of γ-irradiated conidia by two or more incubations at various nonpermissive temperatures alternating with filtrations through cheesecloth. The approximate minimum, optimum, and maximum growth temperatures of the parent were 12, 40, and 50 °C, respectively. Mutants unable to grow at 37 °C were not successfully isolated directly from the wild type. A mutant unable to grow at 25 °C was isolated and mutations further increasing the cold sensitivity by increments of 3–5 °C were found to occur. Mutants completely unable to grow at 37 °C were obtained by five sequential mutations. All mutants grew as fast as the wild-type parent at 45 °C and higher. Each mutant produced revenants able to grow not only at the nonpermissive temperature used for its isolation but also at lower temperatures.

scholarly journals Suppression of ΔbipA Phenotypes in Escherichia coli by Abolishment of Pseudouridylation at Specific Sites on the 23S rRNA

2008 ◽  
Vol 190 (23) ◽  
pp. 7675-7683 ◽  
Author(s):  
Karthik Krishnan ◽  
Ann M. Flower
Keyword(s):  
Escherichia Coli ◽  
Target Genes ◽  
Regulatory Protein ◽  
Elongation Factor ◽  
Direct Interaction ◽  
Cold Sensitivity ◽  
23S Rrna ◽  
Pseudouridine Synthase ◽  
Suppressor Effect ◽  
Cold Sensitive

ABSTRACT The BipA protein of Escherichia coli has intriguing similarities to the elongation factor subfamily of GTPases, including EF-Tu, EF-G, and LepA. In addition, phenotypes of a bipA deletion mutant suggest that BipA is involved in regulation of a variety of pathways. These two points have led to speculation that BipA may be a novel regulatory protein that affects efficient translation of target genes through direct interaction with the ribosome. We isolated and characterized suppressors of the cold-sensitive growth phenotype exhibited by ΔbipA strains and identified insertion mutations in rluC. The rluC gene encodes a pseudouridine synthase responsible for pseudouridine modification of 23S rRNA at three sites, all located near the peptidyl transferase center. Deletion of rluC not only suppressed cold sensitivity but also alleviated the decrease in capsule synthesis exhibited by bipA mutants, suggesting that the phenotypic effects of BipA are manifested through an effect on the ribosome. The suppressor effect is specific to rluC, as deletion of other rlu genes did not relieve cold sensitivity, and further, more than a single pseudouridine residue is involved, as alteration of single residues did not produce suppressors. These results are consistent with a role for BipA in either the structure or the function of the ribosome and imply that wild-type ribosomes are dependent on BipA for efficient expression of target mRNAs and that the lack of pseudouridylation at these three sites renders the ribosomes BipA independent.

scholarly journals Group II intron as cold sensor for self-preservation and bacterial conjugation

2020 ◽  
Vol 48 (11) ◽  
pp. 6198-6209 ◽  
Author(s):  
Xiaolong Dong ◽  
Guosheng Qu ◽  
Carol Lyn Piazza ◽  
Marlene Belfort
Keyword(s):  
Group Ii Intron ◽  
Cold Sensitivity ◽  
Group Ii Introns ◽  
Intron Splicing ◽  
Kinetic Trap ◽  
Group Ii ◽  
Self Splicing ◽  
Mrna Targeting ◽  
Cold Sensor

Abstract Group II introns are self-splicing ribozymes and mobile genetic elements. Splicing is required for both expression of the interrupted host gene and intron retromobility. For the pRS01 plasmid-encoded Lactococcus lactis group II intron, Ll.LtrB, splicing enables expression of the intron's host relaxase protein. Relaxase, in turn, initiates horizontal transfer of the conjugative pRS01 plasmid and stimulates retrotransposition of the intron. Little is known about how splicing of bacterial group II introns is influenced by environmental conditions. Here, we show that low temperatures can inhibit Ll.LtrB intron splicing. Whereas autocatalysis is abolished in the cold, splicing is partially restored by the intron-encoded protein (IEP). Structure profiling reveals cold-induced disruptions of key tertiary interactions, suggesting that a kinetic trap prevents the intron RNA from assuming its native state. Interestingly, while reduced levels of transcription and splicing lead to a paucity of excised intron in the cold, levels of relaxase mRNA are maintained, partially due to diminished intron-mediated mRNA targeting, allowing intron spread by conjugal transfer. Taken together, this study demonstrates not only the intrinsic cold sensitivity of group II intron splicing and the role of the IEP for cold-stress adaptation, but also maintenance of horizontal plasmid and intron transfer under cold-shock.

The association between increasing levels of O-GlcNAc and galectins in the liver tissue of hibernating thirteen-lined ground squirrels (Ictidomys tridecemlineatus)

2020 ◽  
Vol 381 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Komal A. Jariwala ◽  
Ali A. Sherazi ◽  
Rada Tazhitdinova ◽  
Kathryn Shum ◽  
Philipp Guevorguian ◽  
...  
Keyword(s):  
Liver Tissue ◽  
Ground Squirrels ◽  
Ictidomys Tridecemlineatus

Evidence for the involvement of peripheral cold-sensitive TRPM8 channels in human cutaneous hygrosensation

2020 ◽  
Vol 318 (3) ◽  
pp. R579-R589 ◽  
Author(s):  
Oliver Typolt ◽  
Davide Filingeri
Keyword(s):  
Human Skin ◽  
Chemical Activation ◽  
The Body ◽  
Cold Sensitivity ◽  
Trpm8 Channel ◽  
Body Regions ◽  
Skin Cooling ◽  
Cold Sensitive ◽  
Skin Wetness

In contrast to other species, humans are believed to lack hygroreceptors for sensing skin wetness. Yet, the molecular basis of human hygrosensation is currently unknown, and it remains unclear whether we possess a receptor-mediated sensing mechanism for skin wetness. The aim of this study was to assess the role of the cutaneous cold-sensitive transient receptor potential melastatin-8 (TRPM8) channel as a molecular mediator of human hygrosensation. To this end, we exploited both the thermal and chemical activation of TRPM8-expressing cutaneous Aδ cold thermoreceptors, and we assessed wetness sensing in healthy young men in response to 1) dry skin cooling in the TRPM8 range of thermosensitivity and 2) application of the TRPM8 agonist menthol. Our results indicate that 1) independently of contact with moisture, a cold-dry stimulus in the TRPM8 range of activation induced wetness perceptions across 12 different body regions and those wetness perceptions varied across the body following regional differences in cold sensitivity; and 2) independently of skin cooling, menthol-induced stimulation of TRPM8 triggered wetness perceptions that were greater than those induced by physical dry cooling and by contact with an aqueous cream containing actual moisture. For the first time, we show that the cutaneous cold-sensing TRPM8 channel plays the dual role of cold and wetness sensor in human skin and that this ion channel is a peripheral mediator of human skin wetness perception.

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