After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Eur. J. Biochem. 146, 15-22 (1985)[PubMed:3967651]
Human genomic DNA encoding the gamma subunit precursor of the skeletal muscle acetylcholine receptor has been cloned by screening a gene library with a calf cDNA probe and has been subjected to nucleotide sequence analysis. Comparison of the nucleotide sequence of the cloned human genomic DNA with that of the calf cDNA has revealed that the protein-coding sequence of this gene is divided by 11 introns into 12 exons. Evidence is presented to suggest that the human muscle acetylcholine receptor gamma and delta subunit genes are juxtaposed. The primary structure of the gamma subunit precursor of the human muscle acetylcholine receptor has been deduced from the corresponding gene sequence. This polypeptide is composed of 517 amino acids including a hydrophobic prepeptide of 22 amino acids. The gamma subunit of the human muscle acetylcholine receptor, like the alpha subunit of the same receptor as well as the alpha, beta and gamma subunits of its calf counterpart, shares structural features common to all four subunits of the Torpedo electroplax receptor, such as the putative disulphide bridge corresponding to that in the alpha subunit proposed as being in close proximity to the acetylcholine binding site and the four putative, hydrophobic transmembrane segments M1-M4. Thus, the human gamma subunit molecule apparently exhibits the same transmembrane topology as proposed for the fish receptor subunits. The 12 exons seem to correspond to different structural and functional domains of the gamma subunit precursor molecule. Some exons and the protein regions encoded by them are more highly conserved between the mammalian and Torpedo sequences. The pattern of regional homology observed is consistent with the relatively high conservation of the region encompassing the putative disulphide bridge and of the region containing the putative transmembrane segments M1, M2 and M3.
Catalysis of energy-independent facilitated diffusion, mediated by passage of a solute through a transmembrane aqueous pore or channel. Stereospecificity is not exhibited but this transport may be specific for a particular molecular species or class of molecules.
Eur. J. Biochem. 146, 15-22 (1985)[PubMed:3967651]
Human genomic DNA encoding the gamma subunit precursor of the skeletal muscle acetylcholine receptor has been cloned by screening a gene library with a calf cDNA probe and has been subjected to nucleotide sequence analysis. Comparison of the nucleotide sequence of the cloned human genomic DNA with that of the calf cDNA has revealed that the protein-coding sequence of this gene is divided by 11 introns into 12 exons. Evidence is presented to suggest that the human muscle acetylcholine receptor gamma and delta subunit genes are juxtaposed. The primary structure of the gamma subunit precursor of the human muscle acetylcholine receptor has been deduced from the corresponding gene sequence. This polypeptide is composed of 517 amino acids including a hydrophobic prepeptide of 22 amino acids. The gamma subunit of the human muscle acetylcholine receptor, like the alpha subunit of the same receptor as well as the alpha, beta and gamma subunits of its calf counterpart, shares structural features common to all four subunits of the Torpedo electroplax receptor, such as the putative disulphide bridge corresponding to that in the alpha subunit proposed as being in close proximity to the acetylcholine binding site and the four putative, hydrophobic transmembrane segments M1-M4. Thus, the human gamma subunit molecule apparently exhibits the same transmembrane topology as proposed for the fish receptor subunits. The 12 exons seem to correspond to different structural and functional domains of the gamma subunit precursor molecule. Some exons and the protein regions encoded by them are more highly conserved between the mammalian and Torpedo sequences. The pattern of regional homology observed is consistent with the relatively high conservation of the region encompassing the putative disulphide bridge and of the region containing the putative transmembrane segments M1, M2 and M3.
A process in which force is generated within muscle tissue, resulting in a change in muscle geometry. Force generation involves a chemo-mechanical energy conversion step that is carried out by the actin/myosin complex activity, which generates force through ATP hydrolysis.
The specificities of autoantibodies directed against the acetylcholine receptor (AChR) for embryonic and adult muscle AChR were studied in 22 mothers with myasthenia gravis (MG) and in their newborns using human fetus and normal adult muscle AChR preparations. 12 mothers had transmitted MG to their neonates with, in three cases, antenatal injury. A clear correlation was found between occurrence of neonatal MG (NMG) and the high overall level of anti-AChR antibodies (embryonic or adult muscle AChR). However, a strong correlation was also found between occurrence of NMG and the ratio of anti-embryonic AChR to anti-adult muscle (Te/Ta) AChR antibodies (P < 0.0002). Taken together, these data suggest that autoantibodies directed against the embryonic form of the AChR could play a predominant role in the pathogenesis of NMG. Paradoxically, the three cases with antenatal injury presumably the most severe form of NMG, were not associated with high Te/Ta. At the clinical level, these observations could prove helpful in the prediction of transmission of NMG.
Any process that modulates the establishment or extent of a membrane potential, the electric potential existing across any membrane arising from charges in the membrane itself and from the charges present in the media on either side of the membrane.
The cellular process in which a signal is conveyed to trigger a change in the activity or state of a cell. Signal transduction begins with reception of a signal (e.g. a ligand binding to a receptor or receptor activation by a stimulus such as light), or for signal transduction in the absence of ligand, signal-withdrawal or the activity of a constitutively active receptor. Signal transduction ends with regulation of a downstream cellular process, e.g. regulation of transcription or regulation of a metabolic process. Signal transduction covers signaling from receptors located on the surface of the cell and signaling via molecules located within the cell. For signaling between cells, signal transduction is restricted to events at and within the receiving cell.
Eur. J. Biochem. 146, 15-22 (1985)[PubMed:3967651]
Human genomic DNA encoding the gamma subunit precursor of the skeletal muscle acetylcholine receptor has been cloned by screening a gene library with a calf cDNA probe and has been subjected to nucleotide sequence analysis. Comparison of the nucleotide sequence of the cloned human genomic DNA with that of the calf cDNA has revealed that the protein-coding sequence of this gene is divided by 11 introns into 12 exons. Evidence is presented to suggest that the human muscle acetylcholine receptor gamma and delta subunit genes are juxtaposed. The primary structure of the gamma subunit precursor of the human muscle acetylcholine receptor has been deduced from the corresponding gene sequence. This polypeptide is composed of 517 amino acids including a hydrophobic prepeptide of 22 amino acids. The gamma subunit of the human muscle acetylcholine receptor, like the alpha subunit of the same receptor as well as the alpha, beta and gamma subunits of its calf counterpart, shares structural features common to all four subunits of the Torpedo electroplax receptor, such as the putative disulphide bridge corresponding to that in the alpha subunit proposed as being in close proximity to the acetylcholine binding site and the four putative, hydrophobic transmembrane segments M1-M4. Thus, the human gamma subunit molecule apparently exhibits the same transmembrane topology as proposed for the fish receptor subunits. The 12 exons seem to correspond to different structural and functional domains of the gamma subunit precursor molecule. Some exons and the protein regions encoded by them are more highly conserved between the mammalian and Torpedo sequences. The pattern of regional homology observed is consistent with the relatively high conservation of the region encompassing the putative disulphide bridge and of the region containing the putative transmembrane segments M1, M2 and M3.
The directed movement of substances (such as macromolecules, small molecules, ions) into, out of or within a cell, or between cells, or within a multicellular organism by means of some agent such as a transporter or pore.
Eur. J. Biochem. 146, 15-22 (1985)[PubMed:3967651]
Human genomic DNA encoding the gamma subunit precursor of the skeletal muscle acetylcholine receptor has been cloned by screening a gene library with a calf cDNA probe and has been subjected to nucleotide sequence analysis. Comparison of the nucleotide sequence of the cloned human genomic DNA with that of the calf cDNA has revealed that the protein-coding sequence of this gene is divided by 11 introns into 12 exons. Evidence is presented to suggest that the human muscle acetylcholine receptor gamma and delta subunit genes are juxtaposed. The primary structure of the gamma subunit precursor of the human muscle acetylcholine receptor has been deduced from the corresponding gene sequence. This polypeptide is composed of 517 amino acids including a hydrophobic prepeptide of 22 amino acids. The gamma subunit of the human muscle acetylcholine receptor, like the alpha subunit of the same receptor as well as the alpha, beta and gamma subunits of its calf counterpart, shares structural features common to all four subunits of the Torpedo electroplax receptor, such as the putative disulphide bridge corresponding to that in the alpha subunit proposed as being in close proximity to the acetylcholine binding site and the four putative, hydrophobic transmembrane segments M1-M4. Thus, the human gamma subunit molecule apparently exhibits the same transmembrane topology as proposed for the fish receptor subunits. The 12 exons seem to correspond to different structural and functional domains of the gamma subunit precursor molecule. Some exons and the protein regions encoded by them are more highly conserved between the mammalian and Torpedo sequences. The pattern of regional homology observed is consistent with the relatively high conservation of the region encompassing the putative disulphide bridge and of the region containing the putative transmembrane segments M1, M2 and M3.
Protein involved in the transport of ions. Such proteins are usually transmembrane and mediate a movement of ions across cell membranes. Transport may be passive (facilitated diffusion; down the electrochemical gradient), or active (against the electrochemical gradient). Active transport requires energy which may come from light, oxidation reactions, ATP hydrolysis, or cotransport of other ions or molecules.
Protein involved in the transport of a molecule (metabolite, protein, etc), a ion or an electron across cell membranes, inside the cell or in a tissue fluid.
Protein which is part of a transmembrane protein complex that forms a hydrophilic channel across the lipid bilayer through which specific inorganic ions can diffuse down their electrochemical gradients. The channels are usually gated and only open in response to a specific stimulus, such as a change in membrane potential (voltage-gated) or the binding of a ligand (ligand-gated channel).
Protein which forms or is a component of a ligand-gated channel. Ligand-gated channels are transmembrane ion channels whose permeability is increased by the binding of a specific ligand, such as neurotransmitters, ionositol triphosphates, and cyclic nucleotides.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.