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1.
Alpha subunit variants of the human glycine receptor: primary structures, functional expression and chromosomal localization of the corresponding genes. 总被引:31,自引:10,他引:21
G Grenningloh V Schmieden P R Schofield P H Seeburg T Siddique T K Mohandas C M Becker H Betz 《The EMBO journal》1990,9(3):771-776
Two cDNAs encoding variants (alpha 1 and alpha 2) of the strychnine binding subunit of the inhibitory glycine receptor (GlyR) were isolated from a human fetal brain cDNA library. The predicted amino acid sequences exhibit approximately 99% and approximately 76% identity to the previously characterized rat 48 kd polypeptide. Heterologous expression of the human alpha 1 and alpha 2 subunits in Xenopus oocytes resulted in the formation of glycine-gated strychnine-sensitive chloride channels, indicating that both polypeptides can form functional GlyRs. Using a panel of rodent-human hybrid cell lines, the gene encoding alpha 2 was mapped to the short arm (Xp21.2-p22.1) of the human X chromosome. In contrast, the alpha 1 subunit gene is autosomally located. These data indicate molecular heterogeneity of the human GlyR at the level of alpha subunit genes. 相似文献
2.
Victor D. Ramirez Jianbiao Zheng Khawar M. Siddique 《Cellular and molecular neurobiology》1996,16(2):175-198
Summary 1. There are numerous circumstantial evidence supporting the concept that steroid hormones control cellular function by means other than the nuclear receptor steroid binding mechanism. It is the intent of this report to present evidence indicating that steroids bind to specific sites in neuronal membranes.2. Some of the criteria to define steroid membrane receptors using steroid-BSA conjugates that can be radioiodinated to desired specific activity have been fulfilled for each of the three sex steroids using crude synaptosomal membrane preparations (P2 fractions) from the CNS of female and male rats. Ligand binding for each of the three steroids indicate high-affinity and high-capacity sites with distinct brain selectivity and stereospecificity. For example, 17-E-6-[125I]BSA binds hypothalamic P2 fractions (HYP-P2) with an estimatedK
d of about 3±0.7 nM (X ± SE;n=3), whereas the cerebellum P2 (CB-P2) fractions bind the ligand with aK
d of 34±7 nM and, aB
max of 3 and 42 pmol/mg protein, respectively. Estrogen and testosterone binding fit best a one-single site, while progesterone binding sites can be best represented by a two-binding site, one high-affinity (K
d=1–2 nM) and one low affinity (K
d=62 nM), in CB-P2 fractions from intact adult female rat brain. Kinetics studies for T-3-[125I]BSA indicate that the estimatedK
d of 30±2 nM for the olfactory bulb P2 fractions (OB-P2) from male rats is in good agreement withK
d values computed from Scatchard-derived data using the LIGAND algorithm.3. 17-E-6-[125I]BSA binding sites are stereospecific and appears to be present as early as 5 days of age in both the OB- and the CB-P2 fractions without changes during development. In contrast, P-6-[125I]BSA binding sites are practically absent during days 5 and 12 and appear by day 22.4. Finally, membrane receptor molecules for estrogen and progesterone have been isolated and purified by affinity chromatography and characterized by PAGE and Western blot. Microsequencing of one of the membrane estrogen binding proteins indicates that the high-affinity site corresponds to the OSCP subunit of the proton ATP synthase.5. It remains to be determined if P and T also bind to this complex enzyme or if they bind to other subunits of the family of proton ATPases. Overall the data indicate that steroid hormones conjugated to BSA are important tools to study the reality of membrane steroid receptors. 相似文献
3.
The karyomorphology of Podophyllum hexandrum Royle (2n=2x=12) is described for the first time. The haploid set comprises one metacentric, three sub-metacentric and two acrocentric chromosomes. Metacentrics are the longest and acrocentrics the smallest in the complement. Secondary constrictions are located in the short arm of two meta-/submetacentrics and in the long arm of the two acrocentric chromosomes. The number of NORs is in agreement with the number of nucleoli organized per root tip nucleus. 相似文献
4.
Deepti Singh Priyanka Gupta Sneh Lata Singla-Pareek Kadambot H.M. Siddique Ashwani Pareek 《Current Genomics》2021,22(1):59
BackgroundThe two-component signaling (TCS) system is an important signal transduction machinery in prokaryotes and eukaryotes, excluding animals, that uses a protein phosphorylation mechanism for signal transmission.ConclusionProkaryotes have a primitive type of TCS machinery, which mainly comprises a membrane-bound sensory histidine kinase (HK) and its cognate cytoplasmic response regulator (RR). Hence, it is sometimes referred to as two-step phosphorelay (TSP). Eukaryotes have more sophisticated signaling machinery, with an extra component - a histidine-containing phosphotransfer (HPT) protein that shuttles between HK and RR to communicate signal baggage. As a result, the TSP has evolved from a two-step phosphorelay (His–Asp) in simple prokaryotes to a multi-step phosphorelay (MSP) cascade (His–Asp–His–Asp) in complex eukaryotic organisms, such as plants, to mediate the signaling network. This molecular evolution is also reflected in the form of considerable structural modifications in the domain architecture of the individual components of the TCS system. In this review, we present TCS system''s evolutionary journey from the primitive TSP to advanced MSP type across the genera. This information will be highly useful in designing the future strategies of crop improvement based on the individual members of the TCS machinery. 相似文献
5.
Muhammad Arslan Khan Hasan Riaz Muhammad Raheel Qaiser Shakeel Ummara Waheed Nadeem Ahmed Muhammad Bashair Waqas Ashraf Hafiz Tassawar Abbas Maria Siddique Maria Khan Ambreen Naz Musarrat Shaheen Asif Mahmood Arif Habib Ali Muhammad Nasir Mohammad Javed Ansari Hamed A. Ghramh Khalid Ali Khan 《Saudi Journal of Biological Sciences》2021,28(1):1-9
Root-knot nematodes Meloidogyne incognita (Kofoid and White) Chitwood and Rhizoctonia bataticola (Taub.) Butler, fungus, are very dangerous root damaging pathogens. Present study was planned to establish a chemical control of these root deteriorating pathogens under lab conditions as well as in field. Maximum death rate of nematode juveniles and minimum numbers of nematode eggs hatched were recorded in plates treated with Cadusafos (Rugby® 100G) @12 g/100 ml and Cartap® (4% G) @9g/100 ml. Chemical treatment of Rhizoctonia bataticola with Trifloxystrobin + Tebuconazole (Nativo®) @0.2 g/100 ml and Mancozeb + Matalaxyl (Axiom) @0.25 g/100 ml significantly controlled the mycelial growth in plates. The best treatments tested in laboratory were applied in field as protective and curative treatments. Results proved that chemical control of root-knot nematode and root rot fungi by tested chemicals at recommended time and dose is a significant management technique under field conditions. 相似文献
6.
7.
Saima Muzammil Mohsin Khurshid Iqra Nawaz Muhammad Hussnain Siddique Muhammad Zubair Muhammad Atif Nisar 《Biofouling》2020,36(4):492-504
AbstractAcinetobacter baumannii is a biofilm forming multidrug resistant (MDR) pathogen responsible for respiratory tract infections. In this study, aluminium oxide nanoparticles (Al2O3 NPs) were synthesized and characterized by TEM and EDX and shown to be spherical shaped nanoparticles with a diameter < 10?nm. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) for the Al2O3 NPs ranged between 125 and 1,000?µg ml?1. Exposure to NPs caused cellular membrane disruption, indicated by an increase in cellular leakage of the contents. Biofilm inhibition was 11.64 to 70.2%, whereas attachment of bacteria to polystyrene surfaces was reduced to 48.8 to 51.9% in the presence of NPs. Nanoparticles also reduced extracellular polymeric substance production and the biomass of established biofilms. The data revealed the non-toxic nature of Al2O3 NPs up to a concentrations of 120?µg ml?1 in HeLa cell lines. These results demonstrate an effective and safer use of Al2O3 NPs against the MDR A. baumannii by targeting biofilm formation, adhesion and EPS production. 相似文献
8.
Abstract A total of 106 Fusarium spp. were isolated from infected roots and soil samples of wheat and rice. Of the 106 isolates, 32 from wheat, and 74 from rice, were isolated. Six Fusarium spp. (F. oxysporum, F. moniliforme, F. poae, F. graminearum, F. tricinctum and F. equiseti) were identified at specie level. In aggressiveness tests Fusarium spp. root rot causing fungi were screened out into different aggressiveness classes according to disease severity scales. The aggressiveness of Fusarium spp. was studied on wheat varieties (Inqalab-91 and chakwal-86) and on rice varieties (Basmati-385 and IRRI-6) under controlled conditions. The overall total number of aggressive isolates was higher in rice than in wheat. However, the percentage of severely aggressive isolates was high in wheat, whereas the percentage of moderately and slightly aggressiveness isolates was high in rice. In rice, five isolates were non-aggressive and on wheat 17 were non-aggressive. Random Amplified Polymorphism DNAs (RAPDs) were used to study the polymorphism and genetic variations within the population of Fusarium spp. that established to study correlation between taxonomical and genetical characters of fungi. Five random primers were used P1 (5′-AGGAGGACCC-3′), P2 (5′-ACGAGGGACT-3′), PE7 (5′-AGATGCAGCC-3′), P14 (5′-CCACAGCACG-3′) and PE20 (5′-AACGGTGACC-3′). Each of the 10-mer primers produced results based on the respective banding patterns they generated in present investigations. Primers distinguished the F. oxysporum, F. moniliforme, F. graminearum, F. tricinctum, F. poa and F. equiseti. All the tested primers yielded amplification products, and that were reproducible. Although there was some intraspecific variation with primers, some strains were similar and some were different in banding pattern. In F. oxysporum, F. moniliforme, F. graminearum, F. tricinctum, F. poa and F. equiseti were seen clustered close to one another but each primer separated them unambiguously. All primer (P1, P2, P14, PE7 and PE20) combination produced 62 bands. All primers have shown interspecific and intraspecific variations in banding patterns. 相似文献
9.
Abstract Phytophthora infestans is one of the most destructive pathogens of potato and causal agents of notorious disease late blight. Different chemicals are used to control the pathogen of late blight but the most commonly used is metalaxyl; its extensive use of has caused decreased sensitivity in the P. infestans population. The metalaxyl sensitivity of the Pakistani population of P. infestans is investigated in the present study. For this purpose, 178 isolates of P. infestans were obtained from the lesions of diseased potato leaves and stems, and samples were collected from the different potato-growing areas of Pakistan, where late blight is a problem. Sensitivity of the isolates of P. infestans was investigated by metalaxyl sensitivity test and with the help of test isolates were divided into three categories, i.e. sensitive, intermediate and resistant, based on their Co-efficient of mycelial growth inhibition (CMGI) values. During the study, highest percentage (50.17%) of resistant isolates was observed in the population of Punjab (zone 2), whereas the lower percentage (33.33%) was observed in the population of Swat valley (zone 6b). In the present study, it was discovered that P. infestans late blight-causing fungus has adopted more resistance against metalaxyl because of its wide use. 相似文献
10.
Ying L. Chen Vanessa M. Dunbabin Johannes A. Postma Art J. Diggle Kadambot H. M. Siddique Zed Rengel 《Plant and Soil》2013,372(1-2):319-337