Academic literature on the topic 'Mammal osmoregulation by RAS'

The Early Pleistocene locality Muhkai 2 was discovered in Central Dagestan, northeastern Caucasus, Russia, in 2006. Archaeological investigations of the site have been directed by Corresponding member of RAS H.A. Amirkhanov (Institute of Archaeology RAS, Moscow). The article presents the results of the study of osteological material from the excavations of 2006–2017. The cultural layers with stone tools and mammal bones are found within stratum of brownish-grey petrified loams with reversed magnetization. We identified 14 large species of mammals, which are indicators for the dating of the faunal assemblage and crucial in identifying the specific characteristics of the natural environment at the time of site formation. Stenon horse and Etruscan wolf dominate the spectrum of species at Muhkai 2. All large mammal species from the site are inhabitants of open and semi-open landscapes and animals indicative of closed biotopes are absent. The biotope appears to have been a dry savannah-steppe with small areas of forest vegetation. The climate at this time was warm and quite arid. Most likely, the animals died here due to natural causes and their carcasses were buried at the bottom of an ancient, slightly saline and shallow, temporary body of water. Data from the theriofauna place the age of the site Muhkai 2 within the chronological range of 2.1–1.77 Mya.

Activation of the high-osmolarity glycerol (HOG) pathway for osmoregulation in the yeast Saccharomyces cerevisiae involves interaction of the adaptor Ste50p with the cytoplasmic tail of single-transmembrane protein Opy2p. We have determined the solution structure of the Ste50p-RA (Ras association) domain, and it shows an atypical RA fold lacking the β1 and β2 strands of the canonical motif. Although the core of the RA domain is fully functional in the pheromone response, an additional region is required for the HOG pathway activation. Two peptide motifs within the intrinsically disordered cytoplasmic tail of Opy2p defined by NMR spectroscopy physically interact with the Step50p-RA domain. These Opy2p-derived peptides bind overlapping regions of the Step50p-RA domain with similarly weak affinities, suggesting a multivalent interaction of these proteins as a crucial point of control of the HOG pathway. As well, overall selection of signaling pathways depends on functionally distinct regions of the Ste50p-RA domain, implicating this element in the control of global regulatory decisions.

Discriminating among diverse environmental stimuli is critical for organisms to ensure their proper development, homeostasis, and survival. Saccharomyces cerevisiae regulates mating, osmoregulation, and filamentous growth using three different MAPK signaling pathways that share common components and therefore must ensure specificity. The adaptor protein Ste50 activates Ste11p, the MAP3K of all three modules. Its Ras association (RA) domain acts in both hyperosmolar and filamentous growth pathways, but its connection to the mating pathway is unknown. Genetically probing the domain, we found mutants that specifically disrupted mating or HOG-signaling pathways or both. Structurally these residues clustered on the RA domain, forming distinct surfaces with a propensity for protein–protein interactions. GFP fusions of wild-type (WT) and mutant Ste50p show that WT is localized to the shmoo structure and accumulates at the growing shmoo tip. The specifically pheromone response–defective mutants are severely impaired in shmoo formation and fail to localize ste50p, suggesting a failure of association and function of Ste50 mutants in the pheromone-signaling complex. Our results suggest that yeast cells can use differential protein interactions with the Ste50p RA domain to provide specificity of signaling during MAPK pathway activation.

National cancer databases document that melanoma is the most aggressive and deadly cutaneous malignancy with worldwide increasing incidence in the Caucasian population. Around 10% of melanomas occur in families. Several germline mutations were identified that might help to indicate individuals at risk for preventive interventions and early disease detection. More than 50% of sporadic melanomas carry mutations in Ras/Raf/mitogen-activated protein kinase (MAPK/MEK) pathway, which may represent aims of novel targeted therapies. Despite advances in targeted therapies and immunotherapies, the outcomes in metastatic tumor are still unsatisfactory. Here, we review animal models that help our understanding of melanoma development and treatment, including non-vertebrate, mouse, swine, and other mammal models, with an emphasis on those with spontaneously developing melanoma. Special attention is paid to the melanoma-bearing Libechov minipig (MeLiM). This original swine model of hereditary metastatic melanoma enables studying biological processes underlying melanoma progression, as well as spontaneous regression. Current histological, immunohistochemical, biochemical, genetic, hematological, immunological, and skin microbiome findings in the MeLiM model are summarized, together with development of new therapeutic approaches based on tumor devitalization. The ongoing study of molecular and immunological base of spontaneous regression in MeLiM model has potential to bring new knowledge of clinical importance.

The Middle Palaeolithic site Betovo was discovered in the early 1970s by L.M. Tarasov, who summarized data on paleoecology and habitat conditions on this site in a number of publications. However, the stratigraphic position of the deposits containing the cultural layer remained rather uncertain due to the fact that in the sections of the site it was not possible to identify the reference loess-soil horizons and data on the age of the cultural layer were not obtained. A comprehensive study of the site, renewed since 2007 under the direction of archaeologist A. K. Ocherednoi in the frame of the Verkhnyaya Desna expedition of the Institute for the History of Material Culture RAS, permit to detail the deposition rhythmic during the Late Pleistocene and the stratigraphic position of the cultural layers in different parts of the site. By received 14 C data, the site was inhabited in the range of 28.5–36.0 cal kyr BP (calibrated dates), i.e., belongs to the end of the Valdai megainterstadial (the end of MIS 3). The small mammal fauna found in the 2 cultural layer of the Betovo site includes only the tundra and steppe species. The forest species are absent. The species richness of the Betovo fauna is very low, what also indicates the very severe climate during the end of MIS 3 in the Desna River basin. The received mammalian data clearly indicate the extremely harsh natural-climatic conditions of the time of habitation of the ancient man in the site – the conditions of tundra-steppe (“mammoth steppe”).

Media salinity is a masking factor that plays an important role in controlling the process of shrimp molting and osmoregulation. Both of them are ecophysiological factors for shrimp life, so it is necessary to know the optimum level or range of media salinity for each phase of the molting phase changes in the stage and osmoregulation phase. This study was conducted to examine the molting frequency of adult L. vannamei which was ablated and cultivated at various levels of salinity. This research was carried out for 60 days. This study uses experimental laboratory methods with a systematic randomized design (RAS) with 4 treatments and 3 replications in each treatment. The treatments tested were salinity with S1 treatments (10 ppt, 289.20 mOsm / l postmolt H2O isosmotic), S2 (15 ppt, 432.80 mOsm / l H2O initial intermolt isosmotic), S3 (25 ± 1 ppt, 725, 15 mOsm / l H2O isosmotic final intermolt) and S4 (29 ± 1 ppt, 820.10 mOsm / l H2O isosmotic molt). Data were analyzed with ANOVA. Meanwhile, the difference in effect between treatments was obtained through Duncan's multiple area test. ANOVA results showed that various levels of isoosmotic media salinity at various molting phases had an influence (p <0.05) on molting frequency. The best value of molting frequency was in the S4 treatment (29 ± 1 ppt) (close to isoosmotic molt) 10 times. In the maintenance of L. vannamei which is affixed, it should pay attention to the needs of isoosmotic media, namely media with a salinity of 25 ± 1-29 ± 1 ppt (final intermolt isoosmotic range / premolt to molt). the difference in effect between treatments was obtained through Duncan's multiple region test. ANOVA results showed that various levels of isoosmotic media salinity at various molting phases had an influence (p <0.05) on molting frequency. The best value of molting frequency is in the treatment of S4 (29 ± 1 ppt) (close to isoosmotic molt) 10 times. In the maintenance of L. vannamei which is affixed, it is better to pay attention to the needs of isoosmotic media, ie media with a salinity of 25 ± 1-29 ± 1 ppt (final intermolt isoosmotic range / premolt to molt). the difference in effect between treatments was obtained through Duncan's multiple region test. ANOVA results showed that various levels of isoosmotic media salinity at various molting phases had an influence (p <0.05) on molting frequency. The best value of molting frequency is in the treatment of S4 (29 ± 1 ppt) (close to isoosmotic molt) 10 times. In the maintenance of L. vannamei which is affixed, it is better to pay attention to the needs of isoosmotic media, ie media with a salinity of 25 ± 1-29 ± 1 ppt (final intermolt isoosmotic range / premolt to molt). The best value of molting frequency was in the S4 treatment (29 ± 1 ppt) (close to isoosmotic molt) 10 times. In the maintenance of L. vannamei which is affixed, it is better to pay attention to the needs of isoosmotic media, ie media with a salinity of 25 ± 1-29 ± 1 ppt (final intermolt isoosmotic range / premolt to molt). The best value of molting frequency is in the treatment of S4 (29 ± 1 ppt) (close to isoosmotic molt) 10 times. In the maintenance of L. vannamei which is affixed, it is better to pay attention to the needs of isoosmotic media, ie media with a salinity of 25 ± 1-29 ± 1 ppt (final intermolt isoosmotic range / premolt to molt). Keyword : Salinity, Osmoregulation, Molting, L. vannamei, Ablation.Â

Etude chez le rat. Les hormones peptidiques agissent sur les memes cellules que la vasopressine au niveau du segment large ascendant de l'anse de heule (glucagon, calcitonine) et des canaux collecteurs corticaux (calcitonine) et participent a la constitution et au maintien du gradient intrarenal de pression osmotique. Elements nouveaux concernant le mecanisme de concentration de l'urine et sur le recyclage medullaire de k entre les canaux collecteurs et l'anse de heule des nephrons profonds