scholarly journals Elephantid genomes reveal the molecular bases of Woolly Mammoth adaptations to the arctic

2015 ◽  
Author(s):  
Vincent Lynch ◽  
Oscar C. Bedoya-Reina ◽  
Aakrosh Ratan ◽  
Michael Sulak ◽  
Daniela I. Drautz-Moses ◽  
...  

Woolly mammoths and the living elephants are characterized by major phenotypic differences that allowed them to live in very different environments. To identify the genetic changes that underlie the suite of adaptations in woolly mammoths to life in extreme cold, we sequenced the nuclear genome from three Asian elephants and two woolly mammoths, identified and functionally annotated genetic changes unique to the woolly mammoth lineage. We find that genes with mammoth specific amino acid changes are enriched in functions related to circadian biology, skin and hair development and physiology, lipid metabolism, adipose development and physiology, and temperature sensation. Finally we resurrect and functionally test the mammoth and ancestral elephant TRPV3 gene, which encodes a temperature sensitive transient receptor potential (thermoTRP) channel involved in thermal sensation and hair growth, and show that a single mammoth-specific amino acid substitution in an otherwise highly conserved region of the TRPV3 channel strongly affected its temperature sensitivity. Our results have identified a set of genetic changes that likely played important roles in the adaptation of woolly mammoths to life in the high artic.

2001 ◽  
Vol 355 (3) ◽  
pp. 663-670 ◽  
Author(s):  
Claudia TROST ◽  
Christiane BERGS ◽  
Nina HIMMERKUS ◽  
Veit FLOCKERZI

The mammalian gene products, transient receptor potential (trp)1 to trp7, are related to the Drosophila TRP and TRP-like ion channels, and are candidate proteins underlying agonist-activated Ca2+-permeable ion channels. Recently, the TRP4 protein has been shown to be part of native store-operated Ca2+-permeable channels. These channels, most likely, are composed of other proteins in addition to TRP4. In the present paper we report the direct interaction of TRP4 and calmodulin (CaM) by: (1) retention of in vitro translated TRP4 and of TRP4 protein solubilized from bovine adrenal cortex by CaM–Sepharose in the presence of Ca2+, and (2) TRP4–glutathione S-transferase pull-down experiments. Two domains of TRP4, amino acid residues 688–759 and 786–848, were identified as being able to interact with CaM. The binding of CaM to both domains occurred only in the presence of Ca2+ concentrations above 10µM, with half maximal binding occurring at 16.6µM (domain 1) and 27.9µM Ca2+ (domain 2). Synthetic peptides, encompassing the two putative CaM binding sites within these domains and covering amino acid residues 694–728 and 829–853, interacted directly with dansyl–CaM with apparent Kd values of 94–189nM. These results indicate that TRP4/Ca2+-CaM are parts of a signalling complex involved in agonist-induced Ca2+ entry.


2007 ◽  
Vol 292 (1) ◽  
pp. R37-R46 ◽  
Author(s):  
Andrej A. Romanovsky

While summarizing the current understanding of how body temperature (Tb) is regulated, this review discusses the recent progress in the following areas: central and peripheral thermosensitivity and temperature-activated transient receptor potential (TRP) channels; afferent neuronal pathways from peripheral thermosensors; and efferent thermoeffector pathways. It is proposed that activation of temperature-sensitive TRP channels is a mechanism of peripheral thermosensitivity. Special attention is paid to the functional architecture of the thermoregulatory system. The notion that deep Tb is regulated by a unified system with a single controller is rejected. It is proposed that Tb is regulated by independent thermoeffector loops, each having its own afferent and efferent branches. The activity of each thermoeffector is triggered by a unique combination of shell and core Tbs. Temperature-dependent phase transitions in thermosensory neurons cause sequential activation of all neurons of the corresponding thermoeffector loop and eventually a thermoeffector response. No computation of an integrated Tb or its comparison with an obvious or hidden set point of a unified system is necessary. Coordination between thermoeffectors is achieved through their common controlled variable, Tb. The described model incorporates Kobayashi’s views, but Kobayashi’s proposal to eliminate the term sensor is rejected. A case against the term set point is also made. Because this term is historically associated with a unified control system, it is more misleading than informative. The term balance point is proposed to designate the regulated level of Tb and to attract attention to the multiple feedback, feedforward, and open-loop components that contribute to thermal balance.


2006 ◽  
Vol 291 (3) ◽  
pp. R541-R550 ◽  
Author(s):  
Dan Ni ◽  
Qihai Gu ◽  
Hong-Zhen Hu ◽  
Na Gao ◽  
Michael X. Zhu ◽  
...  

A recent study has demonstrated that increasing the intrathoracic temperature from 36°C to 41°C induced a distinct stimulatory and sensitizing effect on vagal pulmonary C-fiber afferents in anesthetized rats ( J Physiol 565: 295–308, 2005). We postulated that these responses are mediated through a direct activation of the temperature-sensitive transient receptor potential vanilloid (TRPV) receptors by hyperthermia. To test this hypothesis, we studied the effect of increasing temperature on pulmonary sensory neurons that were isolated from adult rat nodose/jugular ganglion and identified by retrograde labeling, using the whole cell perforated patch-clamping technique. Our results showed that increasing temperature from 23°C (or 35°C) to 41°C in a ramp pattern evoked an inward current, which began to emerge after exceeding a threshold of ∼34.4°C and then increased sharply in amplitude as the temperature was further increased, reaching a peak current of 173 ± 27 pA ( n = 75) at 41°C. The temperature coefficient, Q10, was 29.5 ± 6.4 over the range of 35–41°C. The peak inward current was only partially blocked by pretreatment with capsazepine (Δ I = 48.1 ± 4.7%, n = 11) or AMG 9810 (Δ I = 59.2 ± 7.8%, n = 8), selective antagonists of the TRPV1 channel, but almost completely abolished (Δ I = 96.3 ± 2.3%) by ruthenium red, an effective blocker of TRPV1–4 channels. Furthermore, positive expressions of TRPV1–4 transcripts and proteins in these neurons were demonstrated by RT-PCR and immunohistochemistry experiments, respectively. On the basis of these results, we conclude that increasing temperature within the normal physiological range can exert a direct stimulatory effect on pulmonary sensory neurons, and this effect is mediated through the activation of TRPV1, as well as other subtypes of TRPV channels.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Robert D. Cohen ◽  
Christopher L. Brown ◽  
Carole Nickols ◽  
Pauline Levey ◽  
Barbara J. Boucher ◽  
...  

The spherical anatomy of human and rat liver lobules implies that more central cells have less time to carry out their function than more peripherally located cells because blood flows past them more rapidly. This problem could be overcome if more centrilobular cells could operate at higher temperatures than periportal cells. This study presents evidence for such a temperature gradient. Firstly, we use mathematical modelling to demonstrate that temperature increases towards the centre of the lobule. Secondly, we examine the distribution of a heat-generating protein and of a heat-sensitive protein across the rat and human liver lobules. Double-antibody staining of healthy liver from rat and human was used for visual scoring and for automated histomorphometric quantitation of the localisation of uncoupling protein-2 (known to generate heat) and of the transient receptor potential-v4 protein (known as a highly temperature-sensitive membrane protein). Both these proteins were found to be located predominantly in the centrilobular region of liver lobules. These findings support the suggestion that temperature gradients across the liver lobule may have evolved as a solution to the problem of reduced contact time between blood and cells at the centre as compared to the periphery of mammalian liver lobules.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Lejla Zubcevic ◽  
William F Borschel ◽  
Allen L Hsu ◽  
Mario J Borgnia ◽  
Seok-Yong Lee

Temperature-sensitive transient receptor potential vanilloid (thermoTRPV) channels are activated by ligands and heat, and are involved in various physiological processes. ThermoTRPV channels possess a large cytoplasmic ring consisting of N-terminal ankyrin repeat domains (ARD) and C-terminal domains (CTD). The cytoplasmic inter-protomer interface is unique and consists of a CTD coiled around a β-sheet which makes contacts with the neighboring ARD. Despite much existing evidence that the cytoplasmic ring is important for thermoTRPV function, the mechanism by which this unique structure is involved in thermoTRPV gating has not been clear. Here, we present cryo-EM and electrophysiological studies which demonstrate that TRPV3 gating involves large rearrangements at the cytoplasmic inter-protomer interface and that this motion triggers coupling between cytoplasmic and transmembrane domains, priming the channel for opening. Furthermore, our studies unveil the role of this interface in the distinct biophysical and physiological properties of individual thermoTRPV subtypes.


2014 ◽  
Author(s):  
Rakesh Kumar Majhi ◽  
Somdatta Saha ◽  
Ashutosh Kumar ◽  
Nirlipta Swain ◽  
Luna Goswami ◽  
...  

Transient Receptor Potential subfamily Melastatin member 8 (TRPM8) is involved in detection of cold temperature and different noxious compounds, execute thermo- as well as chemo-sensitive responses at cellular levels. Here we explored the molecular evolution of TRPM8 by analyzing sequences from different species. We elucidate that different regions of TRPM8 had different levels of selection pressure and the 4-5th transmembrane regions remain highly conserved. Synteny analysis suggests that since vertebrate origin, TRPM8 gene is linked with SPP2, a bone morphogen. We found 16656 TRPM8 variants in 1092 human genomes with top variations are SNPs, insertions and deletions. 692 missense mutations are also mapped to human TRPM8 protein. TRPM8 expresses endogenously in sperm cells of different vertebrates ranging from fish to human. We conclude that TRPM8 has emerged during vertebrate evolution (ca 450 MYA) and sperm-specific expression has guided its molecular evolution. These understandings may have medical importance as well.


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