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Antiporter
An antiporter (also called exchanger or counter-transporter) is a cotransporter and integral membrane protein involved in secondary active transport of two or more different molecules or ions across a phospholipid membrane such as the plasma membrane in opposite directions, one into the cell and one out of the cell. Na+/H+ antiporters have been reviewed. In secondary active transport, one species of solute moves along its electrochemical gradient, allowing a different species to move against its own electrochemical gradient. This movement is in contrast to primary active transport, in which all solutes are moved against their concentration gradients, fueled by ATP. Transport may involve one or more of each type of solute. For example, the Na+/Ca2+ exchanger, found in the plasma membrane of many cells, moves three sodium ions in one direction, and one calcium ion in the other. Role in Homeostatic Mechanisms Na+/H+ Antiporters Antiporters, such as Na+/H+ antiporter protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium–hydrogen Antiporter
The sodium–hydrogen antiporter or sodium–proton exchanger (Na+/H+ exchanger) is a membrane protein that transports Na+ into the cell, and H+ out of the cell ( antiport). Function They are found in the membranes of many cells, and especially in those of the nephron of the kidney, specifically in the intercalary cells of the collecting duct and in the epithelial cells of the proximal convoluted tubule. The membrane pump is primarily responsible for maintaining homeostasis of pH and sodium. Defects in Na+/H+ antiporters may result in heart or kidney failure. Angiotensin II upregulates this antiporter in the proximal convoluted tubule in order to promote Na+ reabsorption and H+ secretion. Na+/H+ exchangers are thought to be implicated in other disorders such as hypertension. In one study, transgenic mice over expressing this membrane protein were shown to have increased reabsorption and retention of sodium after increased salt intake. In dopamine receptor signalling, the wide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiporter
An antiporter (also called exchanger or counter-transporter) is a cotransporter and integral membrane protein involved in secondary active transport of two or more different molecules or ions across a phospholipid membrane such as the plasma membrane in opposite directions, one into the cell and one out of the cell. Na+/H+ antiporters have been reviewed. In secondary active transport, one species of solute moves along its electrochemical gradient, allowing a different species to move against its own electrochemical gradient. This movement is in contrast to primary active transport, in which all solutes are moved against their concentration gradients, fueled by ATP. Transport may involve one or more of each type of solute. For example, the Na+/Ca2+ exchanger, found in the plasma membrane of many cells, moves three sodium ions in one direction, and one calcium ion in the other. Role in Homeostatic Mechanisms Na+/H+ Antiporters Antiporters, such as Na+/H+ antiporter protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotransporter
Cotransporters are a subcategory of membrane transport proteins (transporters) that couple the favorable movement of one molecule with its concentration gradient and unfavorable movement of another molecule against its concentration gradient. They enable active transport#Secondary active transport, coupled or cotransport (secondary active transport) and include antiporters and symporters. In general, cotransporters consist of two out of the three classes of integral membrane proteins known as transporters that move molecules and ions across biomembranes. Uniporters are also transporters but move only one type of molecule down its concentration gradient and are not classified as cotransporters. Background Cotransporters are capable of moving solutes either up or down gradients at rates of 1000 to 100000 molecules per second. They may act as channels or transporters, depending on conditions under which they are assayed. The movement occurs by binding to two molecules or ions at a ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Active Transport
In cellular biology, ''active transport'' is the movement of molecules or ions across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses adenosine triphosphate ( ATP), and secondary active transport that uses an electrochemical gradient. Some examples of active transport include: * Phagocytosis of bacteria by macrophages * Movement of calcium ions out of cardiac muscle cells * Transportation of amino acids across the intestinal lining in the human gut * Secretion of proteins such as enzymes, peptide hormones, and antibodies from various cells * Functioning of white blood cells to defend invading diseases Active cellular transportation (ACT) Unlike passive transport, which uses the kinetic energy and natural entropy of molecules moving down a gradient, active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Active Transport
In cellular biology, ''active transport'' is the movement of molecules or ions across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses adenosine triphosphate ( ATP), and secondary active transport that uses an electrochemical gradient. Some examples of active transport include: * Phagocytosis of bacteria by macrophages * Movement of calcium ions out of cardiac muscle cells * Transportation of amino acids across the intestinal lining in the human gut * Secretion of proteins such as enzymes, peptide hormones, and antibodies from various cells * Functioning of white blood cells to defend invading diseases Active cellular transportation (ACT) Unlike passive transport, which uses the kinetic energy and natural entropy of molecules moving down a gradient, active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NhaD Family
The NhaD familyTC# 2.A.62 belongs to the Ion Transporter (IT) Superfamily. A representative list of proteins belonging to the NhaD family can be found in thTransporter Classification Database The NhaD Na+/H+ antiporter has been characterized from two ''Vibrio'' species: '' V. parahaemolyticus'' and '' V. cholerae'' and in the haloalkaliphile, '' Alkalimonas amylolytica''. These proteins and their homologues are 400-500 aas long and exhibit 10-13 TMSs. They catalyze Na+/H+ and Li+/H+ antiport. They exhibit activity at basic pH (8-10) with no activity at pH 7.5. The ''Amylolytica'' antiporter has low Na+ affinity and has optimal activity at 600 mM Na+. Homologues are found in Pseudomonadota of all groups, '' Flavobacteriia'', and ''Chlamydia.'' Distant homologues of the IT superfamily are ubiquitous. The generalized reaction catalyzed by NhaD is:nH+ (in) + mNa+ (out) ⇌ nH+ (out) + mNa+ (in). See also * Sodium-Proton antiporter * Antiporter * Transporter Classification Data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uniporter
A uniporter is a membrane transport protein that transports a single species of Substrate (biochemistry), substrate (Electric charge, charged or uncharged) across a cell membrane. It may use either facilitated diffusion and transport along a diffusion gradient or transport against one with an active transport process. Uniporters include both carriers and ion channels, and are referred to as facilitated transporters, suggesting movement down a concentration or electrochemical gradient. Uniporter carrier proteins work by binding to one molecule of substrate (biochemistry), substrate at a time. Uniporter channels open in response to a stimulus and allow the free flow of specific molecules. There are several ways in which the opening of uniporter channels may be regulated: # Voltage – Regulated by the difference in voltage across the membrane # Stress (physics), Stress – Regulated by physical pressure on the transporter (as in the cochlea of the ear) # Ligand – Regulated by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NhaB Family
The NhaB familyTC# 2.A.34 belongs to the Ion transporter superfamily, ion transporter (IT) superfamily. A representative list of proteins belonging to the NhaB family can be found in thTransporter Classification Database NhaB homologues are usually about 500 aminoacyl residues (aas) in length and possess about 12 transmembrane alpha-helical spanners (TMSs), although some members differ in their number of TMSs. NhaB homologues also exhibit a region with limited sequence similarity to a 46 kDa membrane protein of unknown function from ''Mycobacterium leprae'' (spP46838) which is also homologous to a member of arsenate resistance pumps of bacteria, archaea and eukaryotesTC# 3.A.4. Only gram-negative bacterial proteins have been functionally characterized. The ''E. coli'' NhaB is 58% identical to the orthologous ''Vibrio alginolyticus'' Na+/H+ antiporter. Although the latter protein is predicted to exhibit 10 TMSs, construction of ''NhaB-phoA'' fusions led to evidence for a 9 TMS model ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium-calcium Exchanger
The sodium-calcium exchanger (often denoted Na+/Ca2+ exchanger, exchange protein, or NCX) is an antiporter membrane protein that removes calcium from cells. It uses the energy that is stored in the electrochemical gradient of sodium (Na+) by allowing Na+ to flow down its gradient across the plasma membrane in exchange for the countertransport of calcium ions (Ca2+). A single calcium ion is exported for the import of three sodium ions. The exchanger exists in many different cell types and animal species. The NCX is considered one of the most important cellular mechanisms for removing Ca2+. The exchanger is usually found in the plasma membranes and the mitochondria and endoplasmic reticulum of excitable cells. Function The sodium–calcium exchanger is only one of the systems by which the cytoplasmic concentration of calcium ions in the cell is kept low. The exchanger does not bind very tightly to Ca2+ (has a low affinity), but it can transport the ions rapidly (has a high capa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symporter
A symporter is an integral membrane protein that is involved in the transport of two (or more) different molecules across the cell membrane in the same direction. The symporter works in the plasma membrane and molecules are transported across the cell membrane at the same time, and is, therefore, a type of cotransporter. The transporter is called a symporter, because the molecules will travel in the same direction in relation to each other. This is in contrast to the antiport transporter. Typically, the ion(s) will move down the electrochemical gradient, allowing the other molecule(s) to move against the concentration gradient. The movement of the ion(s) across the membrane is facilitated diffusion, and is coupled with the active transport of the molecule(s). In symport, two molecule move in 'similar direction' at the 'same time' Example of symport:- movement of glucose along with sodium ion Examples SGLT1 in the intestinal epithelium transports sodium ions (Na+) and glucose acro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escherichia Coli
''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escherichia'' that is commonly found in the lower intestine of warm-blooded organisms. Most ''E. coli'' strains are harmless, but some serotypes ( EPEC, ETEC etc.) can cause serious food poisoning in their hosts, and are occasionally responsible for food contamination incidents that prompt product recalls. Most strains do not cause disease in humans and are part of the normal microbiota of the gut; such strains are harmless or even beneficial to humans (although these strains tend to be less studied than the pathogenic ones). For example, some strains of ''E. coli'' benefit their hosts by producing vitamin K2 or by preventing the colonization of the intestine by pathogenic bacteria. These mutually beneficial relationships between ''E. col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porters
Porters may refer to: * Porters, Virginia, an unincorporated community in Virginia, United States * Porters, Wisconsin, an unincorporated community in Wisconsin, United States * Porters Ski Area, a ski resort in New Zealand * ''Porters'' (TV series), a British TV series See also * *Miss Porter's School Miss Porter's School (MPS) is an elite American private college preparatory school for girls founded in 1843, and located in Farmington, Connecticut. The school draws students from 21 states, 31 countries (with dual-citizenship and/or residence), ..., also known as Porter's, a school in Connecticut, United States * Porter (other) {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
