المؤلفون: Zhongying Wang, Qingping Ma, Jiawen Lu, Xiaochen Cui, Haifeng Chen, Hao Wu, Zhiwu Huang

المصدر: Frontiers in Cell and Developmental Biology, Vol 9 (2021)

مصطلحات موضوعية: prestin orthologs, high-frequency hearing limit (Fmax), non-linear capacitance, whole cell patch-clamp, 3D protein structure, Biology (General), QH301-705.5

الوصف: Among the vertebrate lineages with different hearing frequency ranges, humans lie between the low-frequency hearing (1 kHz) of fish and amphibians and the high-frequency hearing (100 kHz) of bats and dolphins. Little is known about the mechanism underlying such a striking difference in the limits of hearing frequency. Prestin, responsible for cochlear amplification and frequency selectivity in mammals, seems to be the only candidate to date. Mammalian prestin is densely expressed in the lateral plasma membrane of the outer hair cells (OHCs) and functions as a voltage-dependent motor protein. To explore the molecular basis for the contribution of prestin in hearing frequency detection, we collected audiogram data from humans, dogs, gerbils, bats, and dolphins because their average hearing frequency rises in steps. We generated stable cell lines transfected with human, dog, gerbil, bat, and dolphin prestins (hPres, dPres, gPres, bPres, and nPres, respectively). The non-linear capacitance (NLC) of different prestins was measured using a whole-cell patch clamp. We found that the Qmax/Clin of bPres and nPres was significantly higher than that of humans. The V1/2 of hPres was more hyperpolarized than that of nPres. The z values of hPres and bPres were higher than that of nPres. We further analyzed the relationship between the high-frequency hearing limit (Fmax) and the functional parameters (V1/2, z, and Qmax/Clin) of NLC among five prestins. Interestingly, no significant correlation was found between the functional parameters and Fmax. Additionally, a comparative study showed that the amino acid sequences and tertiary structures of five prestins were quite similar. There might be a common fundamental mechanism driving the function of prestins. These findings call for a reconsideration of the leading role of prestin in hearing frequency perception. Other intriguing kinetics underlying the hearing frequency response of auditory organs might exist.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fcell.2021.638530/fullTest; https://doaj.org/toc/2296-634XTest

الوصول الحر: https://doaj.org/article/038be4de4b0c4d29bb4ab7718ac9aaf6Test

المؤلفون: Ana Pantelić, Strahinja Stevanović, Sonja Milić Komić, Nataša Kilibarda, Marija Vidović

المصدر: International Journal of Molecular Sciences, Vol 23, Iss 7, p 3547 (2022)

مصطلحات موضوعية: 3D protein structure modelling, de novo transcriptome assembly, differentially expressed gene analysis, drought, intrinsically disordered proteins, liquid–liquid phase separation, Biology (General), QH301-705.5, Chemistry, QD1-999

الوصف: Ramonda serbica Panc. is an ancient resurrection plant able to survive a long desiccation period and recover metabolic functions upon watering. The accumulation of protective late embryogenesis abundant proteins (LEAPs) is a desiccation tolerance hallmark. To propose their role in R. serbica desiccation tolerance, we structurally characterised LEAPs and evaluated LEA gene expression levels in hydrated and desiccated leaves. By integrating de novo transcriptomics and homologues LEAP domains, 318 R. serbica LEAPs were identified and classified according to their conserved motifs and phylogeny. The in silico analysis revealed that hydrophilic LEA4 proteins exhibited an exceptionally high tendency to form amphipathic α-helices. The most abundant, atypical LEA2 group contained more hydrophobic proteins predicted to fold into the defined globular domains. Within the desiccation-upregulated LEA genes, the majority encoded highly disordered DEH1, LEA1, LEA4.2, and LEA4.3 proteins, while the greatest portion of downregulated genes encoded LEA2.3 and LEA2.5 proteins. While dehydrins might chelate metals and bind DNA under water deficit, other intrinsically disordered LEAPs might participate in forming intracellular proteinaceous condensates or adopt amphipathic α-helical conformation, enabling them to stabilise desiccation-sensitive proteins and membranes. This comprehensive LEAPs structural characterisation is essential to understanding their function and regulation during desiccation aiming at crop drought tolerance improvement.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/1422-0067/23/7/3547Test; https://doaj.org/toc/1661-6596Test; https://doaj.org/toc/1422-0067Test

الوصول الحر: https://doaj.org/article/18dd2fc985434617a86285828215ebf8Test

المؤلفون: Edmund Kozieł, Katarzyna Otulak-Kozieł, Józef J. Bujarski

المصدر: International Journal of Molecular Sciences, Vol 19, Iss 9, p 2570 (2018)

مصطلحات موضوعية: viral intercellular transport, immunolocalization, plasmodesmata, 3D protein structure, Prune dwarf virus, Biology (General), QH301-705.5, Chemistry, QD1-999

الوصف: Prune dwarf virus (PDV) is an important viral pathogen of plum, sweet cherry, peach, and many herbaceous test plants. Although PDV has been intensively investigated, mainly in the context of phylogenetic relationship of its genes and proteins, many gaps exist in our knowledge about the mechanism of intercellular transport of this virus. The aim of this work was to investigate alterations in cellular organelles and the cell-to-cell transport of PDV in Cucumis sativus cv. Polan at ultrastructural level. To analyze the role of viral proteins in local transport, double-immunogold assays were applied to localize PDV coat protein (CP) and movement protein (MP). We observe structural changes in chloroplasts, mitochondria, and cellular membranes. We prove that PDV is transported as viral particles via MP-generated tubular structures through plasmodesmata. Moreover, the computer-run 3D modeling reveals structural resemblances between MPs of PDV and of Alfalfa mosaic virus (AMV), implying similarities of transport mechanisms for both viruses.

العلاقة: http://www.mdpi.com/1422-0067/19/9/2570Test; https://doaj.org/toc/1422-0067Test; https://doaj.org/article/8a196a28c9104c91a6d41b9c77bb02b1Test

الإتاحة: https://doi.org/10.3390/ijms19092570Test
https://doaj.org/article/8a196a28c9104c91a6d41b9c77bb02b1Test

المؤلفون: Zhongying Wang, Qingping Ma, Jiawen Lu, Xiaochen Cui, Haifeng Chen, Hao Wu, Zhiwu Huang

المصدر: Frontiers in Cell and Developmental Biology
Frontiers in Cell and Developmental Biology, Vol 9 (2021)

مصطلحات موضوعية: 0301 basic medicine, medicine.medical_specialty, Frequency selectivity, QH301-705.5, non-linear capacitance, Biology, Audiology, Gerbil, 03 medical and health sciences, Cell and Developmental Biology, 0302 clinical medicine, Frequency detection, medicine, otorhinolaryngologic diseases, Patch clamp, Biology (General), Outer hair cells, Prestin, Original Research, prestin orthologs, high-frequency hearing limit (Fmax), Lateral plasma membrane, Cell Biology, Audiogram, 3D protein structure, 030104 developmental biology, biology.protein, sense organs, whole cell patch-clamp, 030217 neurology & neurosurgery, Developmental Biology

الوصف: Among the vertebrate lineages with different hearing frequency ranges, humans lie between the low-frequency hearing (1 kHz) of fish and amphibians and the high-frequency hearing (100 kHz) of bats and dolphins. Little is known about the mechanism underlying such a striking difference in the limits of hearing frequency. Prestin, responsible for cochlear amplification and frequency selectivity in mammals, seems to be the only candidate to date. Mammalian prestin is densely expressed in the lateral plasma membrane of the outer hair cells (OHCs) and functions as a voltage-dependent motor protein. To explore the molecular basis for the contribution of prestin in hearing frequency detection, we collected audiogram data from humans, dogs, gerbils, bats, and dolphins because their average hearing frequency rises in steps. We generated stable cell lines transfected with human, dog, gerbil, bat, and dolphin prestins (hPres, dPres, gPres, bPres, and nPres, respectively). The non-linear capacitance (NLC) of different prestins was measured using a whole-cell patch clamp. We found that the Qmax/Clin of bPres and nPres was significantly higher than that of humans. The V1/2 of hPres was more hyperpolarized than that of nPres. The z values of hPres and bPres were higher than that of nPres. We further analyzed the relationship between the high-frequency hearing limit (Fmax) and the functional parameters (V1/2, z, and Qmax/Clin) of NLC among five prestins. Interestingly, no significant correlation was found between the functional parameters and Fmax. Additionally, a comparative study showed that the amino acid sequences and tertiary structures of five prestins were quite similar. There might be a common fundamental mechanism driving the function of prestins. These findings call for a reconsideration of the leading role of prestin in hearing frequency perception. Other intriguing kinetics underlying the hearing frequency response of auditory organs might exist.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::eabf37683a277b52cf8e36d5c79592b2Test
https://pubmed.ncbi.nlm.nih.gov/34046403Test