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151.
Scott T. Sayers Hock C. Yeoh Jerry A. McLane Irene R. Held 《Neurochemical research》1988,13(12):1125-1131
The acetylcholine receptor (AChR) content and the autorphosphorylation of the regulatory subunit of cyclic AMP-dependent protein kinase type II (R-II) were evaluated in rat soleus muscles at 24, 30 and 66 hr after surgical denervation by cutting the nerve at a short distance (short-nerve-stump) and at a long distance (long-nerve-stump) from the muscle. AChR content was based on the specific binding of [125I]alpha-bungarotoxin (BUTX); changes in the autophosphorylation of R-II were based upon the predominant in vitro32P-phosphorylation of a 56-Kd soluble protein in cytosolic fractions of solei. The AChR content and the32P-autophosphorylation of R-II were increased in samples from short-nerve-stump solei, but not from long-nerve-stump solei, after a denervation-time of 30 hr. This nerve-stump-length dependency indicates that the two denervation effects are not related to the immediate halt of impulse-evoked muscle contractility. Furthermore, the results show that alterations in the32P-autophosphorylation of R-II occurred before, as well as whenever, increases in the AChR content were found. Speculatively, this temporal relationship may be significant with respect to the potential role of R-II in gene expression.Abbreviations ACh
acetylcholine
- AChR
acetylcholine receptor(s)
- BUTX
alpha-bungarotoxin
- Kd
kilodalton
- PAGE
polyacrylamide gel electrophoresis
- R-II
regulatory subunit of cyclic AMP-dependent protein kinase type II
- SDS
sodium dodecyl sulfate 相似文献
152.
Abstract. The techniques of molecular biology are being employed to investigate at the gene level the systemically mediated, wound-induced accumulation of two defensive proteinase inhibitor proteins in plant leaves. These techniques have added a new dimension to biochemical and physiological studies already underway to understand the mechanism of induction by wounding. The acquisition of cDNAs from the RNAs coding for the two inhibitors facilitated studies of mRNA synthesis in leaves in response to wounding, and provided probes to obtain wound-inducible proteinase inhibitor genes from tomato ( Lycopersicon esculentum ) and potato (Solarium tuberosum) genomes. Successful transformations of tobacco plants with fused genes, containing the 5' and 3' regions of the inhibitor genes with the open reading frame of the chloramphenicol acelyltransferase ( cat ) gene, have provided a wound-inducible chloramphenicol acetyltransferase (CATase) activity with which to seek cis- and transacting elements that regulate wound-inducibility to help to understand the interaction of cytoplasmic and nuclear components of the intracellular communication systems that activate the proteinase inhibitor genes in response to wounding by insect pests. 相似文献
153.
A role for haemoglobin in all plant roots? 总被引:4,自引:2,他引:2
Abstract. We have found haemoglobin in plant roots whereas previously it has been recorded only in nitrogen fixing nodules of plants. Haemoglobin occurs not only in the roots of those plants that are capable of nodulation but also in the roots of species that are not known to nodulate. We suggest that a haemoglobin gene may be a component of the genome of all plants. The gene structure and sequence in two unrelated families of plants suggests that the plant haemoglobins have had a single origin and that this origin relates to the haemoglobin gene of the animal kingdom. At present we cannot completely rule out the possibility of a horizontal transfer of the gene from the animal kingdom to a progenitor of the dicotyledonous angiosperms but we favour a single origin of the gene from a progenitor organism to both the plant and animal kingdoms. We speculate about the possible functions of haemoglobin in plant roots and put the case that it is unlikely to have a function in facilitating oxygen diffusion. We suggest that haemoglobin may act as a signal molecule indicating oxygen deficit and the consequent need to shift plant metabolism from an oxidative to a fermentative pathway of energy generation. 相似文献
154.
The comparison of primary structures is extended to 22 cytochromesb orb
6, 12 cytochromesc
1 orf, and 8 Rieske FeS proteins. Conclusions are drawn as to their phylogenetic relationship as well as on conserved, functionally important amino acids and secondary structures. The results are in favor of two independent quinone binding sites at opposite surfaces of the membrane, topping one of the two hemes of cytochromeb each. 相似文献
155.
156.
157.
Leo S. Melchers Dave V. Thompson Ken B. Idler Saskia T. C. Neuteboom Ruud A. de Maagd Rob A. Schilperoort Paul J. J. Hooykaas 《Plant molecular biology》1988,11(2):227-237
The virulence loci play an essential role in tumor formation by Agrobacterium tumefaciens. Induction of vir gene expression by plant signal molecules is solely dependent on the virulence loci virA and virG. This study focused on the virA locus of the octopine type Ti plasmid pTi15955. The nucleic acid sequence of a 5.7-kilobase fragment encompassing virA was determined. Genetic analysis of this region revealed that virA contains one open reading frame coding for a protein of 91 639 daltons. Immunodetection with antibodies raised against a 35-kDa VirA fusion protein produced in E. coli identified the VirA product in wild-type Agrobacterium cells. Moreover, it is shown that the VirA protein is located in the cytoplasmic membrane fraction of Agrobacterium. These data confirm the proposed regulatory function of VirA whereby VirA acts as a membrane sensor protein to identify plant signal molecules in the environment. The proposed sensory function of VirA strikingly resembles the function of the chemotaxis receptor proteins of E. coli. 相似文献
158.
In this article it is shown that the T-DNA of Agrobacterium tumefaciens contains besides the well-known cyt and aux genes another gene with an oncogenic effect in plants. The gene in question is called 6b and causes the formation of small tumors in plant species such as Nicotiana glauca and Kalanchoe tubiflora. 相似文献
159.
160.