|
KCNN4
Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 4, also known as KCNN4, is a human gene encoding the KCa3.1 protein. Function The KCa3.1 protein is part of a potentially heterotetrameric voltage-independent potassium channel that is activated by intracellular calcium. Activation is followed by membrane hyperpolarization, which promotes calcium influx. The encoded protein may be part of the predominant calcium-activated potassium channel in T-lymphocytes. This gene is similar to other KCNN family potassium channel genes, but it differs enough to possibly be considered as part of a new subfamily. History The channel activity was first described in 1958 by György Gárdos in human erythrocytes. The channel is also named Gardos channel because of its discoverer. See also * SK channel * Voltage-gated potassium channel * Senicapoc Senicapoc (ICA-17043) is a Gardos channel blocker. It has been proposed for use in sickle cell anemia. Gard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SK Channel
SK channels (small conductance calcium-activated potassium channels) are a subfamily of calcium-activated potassium channels. They are so called because of their small single channel conductance in the order of 10 pS. SK channels are a type of ion channel allowing potassium cations to cross the cell membrane and are activated (opened) by an increase in the concentration of intracellular calcium through N-type calcium channels. Their activation limits the firing frequency of action potentials and is important for regulating afterhyperpolarization in the neurons of the central nervous system as well as many other types of electrically excitable cells. This is accomplished through the hyperpolarizing leak of positively charged potassium ions along their concentration gradient into the extracellular space. This hyperpolarization causes the membrane potential to become more negative. SK channels are thought to be involved in synaptic plasticity and therefore play important roles in l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium-activated Potassium Channel
Calcium-activated potassium channels are potassium channels gated by calcium, or that are structurally or phylogenetically related to calcium gated channels. They were first discovered in 1958 by Gardos who saw that calcium levels inside of a cell could affect the permeability of potassium through that cell membrane. Then in 1970, Meech was the first to observe that intracellular calcium could trigger potassium currents. In humans they are divided into three subtypes: BK channel, large conductance or BK channels, which have very high conductance which range from 100 to 300 pS, intermediate conductance or IK channels, with intermediate conductance ranging from 25 to 100 pS, and small conductance or SK channels with small conductances from 2-25 pS. This family of ion channels is, for the most part, activated by intracellular Ca2+ and contains 8 members in the human genome. However, some of these channels (the KCa4 and KCa5 channels) are responsive instead to other intracellular ligan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Senicapoc
Senicapoc (ICA-17043) is a Gardos channel blocker. It has been proposed for use in sickle cell anemia. Gardos channel blockers may work in the treatment of sickle cell anemia by blocking the efflux of potassium and water from red blood cells, thereby preventing the dehydration of red blood cells and stopping the polymerization of HbS. The Gardos channel has been identified as KCNN4 Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 4, also known as KCNN4, is a human gene encoding the KCa3.1 protein. Function The KCa3.1 protein is part of a potentially heterotetrameric voltage-independ .... The "ICA" is for Icagen, which is developing the drug. References Fluoroarenes Acetamides {{blood-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythrocytes
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "hollow vessel", with ''-cyte'' translated as "cell" in modern usage), are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system. RBCs take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillaries. The cytoplasm of a red blood cell is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Channel
Potassium channels are the most widely distributed type of ion channel found in virtually all organisms. They form potassium-selective pores that span cell membranes. Potassium channels are found in most cell types and control a wide variety of cell functions. Function Potassium channels function to conduct potassium ions down their electrochemical gradient, doing so both rapidly (up to the diffusion rate of K+ ions in bulk water) and selectively (excluding, most notably, sodium despite the sub-angstrom difference in ionic radius). Biologically, these channels act to set or reset the resting potential in many cells. In excitable cells, such as neurons, the delayed counterflow of potassium ions shapes the action potential. By contributing to the regulation of the cardiac action potential duration in cardiac muscle, malfunction of potassium channels may cause life-threatening arrhythmias. Potassium channels may also be involved in maintaining vascular tone. They also regulate ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium In Biology
Calcium ions (Ca2+) contribute to the physiology and biochemistry of organisms' cell (biology), cells. They play an important role in signal transduction pathways, where they act as a second messenger, in neurotransmitter release from neurons, in contraction of all muscle cell types, and in fertilization. Many enzymes require calcium ions as a Cofactor (biochemistry), cofactor, including several of the coagulation factors. Extracellular calcium is also important for maintaining the potential difference across excitable cell cell membrane, membranes, as well as proper bone formation. Plasma calcium levels in mammals are tightly regulated, electronic-book electronic- with bone acting as the major mineral storage site. Calcium ions, Ca2+, are released from bone into the bloodstream under controlled conditions. Calcium is transported through the bloodstream as dissolved ions or bound to proteins such as serum albumin. Parathyroid hormone secreted by the parathyroid gland regulates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Cell
A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface. T cells are born from hematopoietic stem cells, found in the bone marrow. Developing T cells then migrate to the thymus gland to develop (or mature). T cells derive their name from the thymus. After migration to the thymus, the precursor cells mature into several distinct types of T cells. T cell differentiation also continues after they have left the thymus. Groups of specific, differentiated T cell subtypes have a variety of important functions in controlling and shaping the immune response. One of these functions is immune-mediated cell death, and it is carried out by two major subtypes: CD8+ "killer" and CD4+ "helper" T cells. (These are named for the presence of the cell surface proteins CD8 or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
György Gárdos
György () is a Hungarian version of the name ''George''. Some notable people with this given name: * György Alexits, as a Hungarian mathematician * György Almásy, Hungarian asiologist, traveler, zoologist and ethnographer, father of László Almásy * György Apponyi, Hungarian politician * György Gordon Bajnai, Prime Minister of Hungary (2009-10) * György Bálint (originally surname Braun; 1919–2020), Hungarian horticulturist, Candidate of Agricultural Sciences, journalist, author, and politician who served as an MP. * György Bárdy, Hungarian film and television actor * György Békésy, Hungarian biophysicist, awarded the Nobel Prize in Physiology or Medicine * György Bessenyei, Hungarian playwright and poet * György Bródy, Hungarian water polo goalkeeper, 2x Olympic champion * György Bulányi, Hungarian a Piarist priest, teacher, and leader * György Carabelli, Hungarian dentist * György Csányi, Hungarian athlete * György Cserhalmi, Hungarian actor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage-gated Potassium Channel
Voltage-gated potassium channels (VGKCs) are transmembrane channels specific for potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized cell to a resting state. Classification Alpha subunits Alpha subunits form the actual conductance pore. Based on sequence homology of the hydrophobic transmembrane cores, the alpha subunits of voltage-gated potassium channels are grouped into 12 classes. These are labeled Kvα1-12. The following is a list of the 40 known human voltage-gated potassium channel alpha subunits grouped first according to function and then subgrouped according to the Kv sequence homology classification scheme: Delayed rectifier slowly inactivating or non-inactivating *Kvα1.x - Shaker-related: Kv1.1 (KCNA1), Kv1.2 (KCNA2), Kv1.3 (KCNA3), Kv1.5 (KCNA5), Kv1.6 (KCNA6), Kv1.7 ( KCNA7), Kv1.8 (KCNA10) *Kvα2.x - Shab-related: Kv2.1 (KCNB1), Kv2.2 (KCNB2) *Kvα3.x - ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
