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WNK4
Serine/threonine protein kinase WNK4 also known as WNK lysine deficient protein kinase 4 or WNK4, is an enzyme that in humans is encoded by the ''WNK4'' gene. Missense mutations cause a genetic form of pseudohypoaldosteronism type 2, also called Gordon syndrome. WNK4 is a member of a serine/threonine kinase family that comprises four members. The family is so named because unlike other serine/threonine kinases, WNKs are characterized by the lack of the lysine in the subdomain II of the catalytic domain. Instead, a lysine in the β2 strand of subdomain I of the catalytic domain is responsible for the kinase activity. The ''WNK4'' gene is located on chromosome 17q21-q22. It produces a 1,243-amino acid protein encoded by a 3,732-nucleotide open reading frame within a 4 kb cDNA transcript. WNK4 protein is highly expressed in the distal convoluted tubule (DCT) and the cortical collecting duct (CDD) of the kidney. WNK4 is also present in the brain, lungs, liver, heart, and colon of vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WNK1
WNK (lysine deficient protein kinase 1), also known as WNK1, is an enzyme that is encoded by the ''WNK1'' gene. WNK1 is serine-threonine protein kinase and part of the "with no lysine/K" kinase WNK family. The predominant role of WNK1 is the regulation of cation-Cl− cotransporters (CCCs) such as the sodium chloride cotransporter (NCC), basolateral Na-K-Cl symporter ( NKCC1), and potassium chloride cotransporter (KCC1) located within the kidney. CCCs mediate ion homeostasis and modulate blood pressure by transporting ions in and out of the cell. ''WNK1'' mutations as a result have been implicated in blood pressure disorders/diseases; a prime example being familial hyperkalemic hypertension (FHHt). Structure The WNK1 protein is composed of 2382 amino acids (molecular weight 230 kDa). The protein contains a kinase domain located within its short N-terminaldomain and a long C-terminal tail. The kinase domain has some similarity to the MEKK protein kinase family. As a member ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudohypoaldosteronism
Pseudohypoaldosteronism (PHA) is a condition that mimics hypoaldosteronism. However, the condition is due to a failure of ''response'' to aldosterone, and levels of aldosterone are actually elevated, due to a lack of feedback inhibition. Types Presentation PHA2 is clinically characterised by hypertension, hyperkalaemia, metabolic acidosis and normal renal function. Mechanism PHA2 is also known as familial hyperkalaemic hypertension, or Gordon syndrome. The underlying genetic defect leads to increased sodium chloride reabsorption in the distal tubule in the kidney, leading to volume expansion, hypertension and lowered renin levels. The hyperkalemia found in PHA2 is proposed to be a function of diminished sodium delivery to the cortical collecting tubule (potassium excretion is mediated by the renal outer medullary potassium channel ROMK in which sodium reabsorption plays a role). Alternatively, WNK4 mutations that result in a gain of function of the Na-Cl co-transporter may inhi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Kinase Domain
The protein kinase domain is a structurally conserved protein domain containing the catalytic function of protein kinases. Protein kinases are a group of enzymes that move a phosphate group onto proteins, in a process called phosphorylation. This functions as an on/off switch for many cellular processes, including metabolism, transcription, cell cycle progression, cytoskeletal rearrangement and cell movement, apoptosis, and differentiation. They also function in embryonic development, physiological responses, and in the nervous and immune system. Abnormal phosphorylation causes many human diseases, including cancer, and drugs that affect phosphorylation can treat those diseases. Protein kinases possess a catalytic subunit which transfers the gamma phosphate from nucleoside triphosphates (almost always ATP) to the side chain of an amino acid in a protein, resulting in a conformational and/or dynamic changes affecting protein function. These enzymes fall into two broad classes, char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distal Convoluted Tubule
The distal convoluted tubule (DCT) is a portion of kidney nephron between the loop of Henle and the collecting tubule. Physiology It is partly responsible for the regulation of potassium, sodium, calcium, and pH. On its apical surface (lumen side), cells of the DCT have a thiazide-sensitive Na-Cl cotransporter and are permeable to Ca, via the TRPV5 channel. On the basolateral surface (peritubular capillary side) there is an ATP-dependent Na/K antiporter pump, a secondary active Na/Ca transporter, and an ATP dependent Ca transporter. The basolateral ATP dependent Na/K pump produces the gradient for Na to be absorbed from the apical surface via the Na/Cl symporter, and for Ca to be reclaimed into the blood by the Na/Ca basolateral antiporter. * It regulates pH by absorbing bicarbonate and secreting protons (H+) into the filtrate, or by absorbing protons and secreting bicarbonate into the filtrate. * Sodium and potassium levels are controlled by secreting K+ and absorbing N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coiled Coil
A coiled coil is a structural motif in proteins in which 2–7 alpha-helices are coiled together like the strands of a rope. ( Dimers and trimers are the most common types.) Many coiled coil-type proteins are involved in important biological functions, such as the regulation of gene expression — e.g., transcription factors. Notable examples are the oncoproteins c-Fos and c-Jun, as well as the muscle protein tropomyosin. Discovery The possibility of coiled coils for α-keratin was initially somewhat controversial. Linus Pauling and Francis Crick independently came to the conclusion that this was possible at about the same time. In the summer of 1952, Pauling visited the laboratory in England where Crick worked. Pauling and Crick met and spoke about various topics; at one point, Crick asked whether Pauling had considered "coiled coils" (Crick came up with the term), to which Pauling said he had. Upon returning to the United States, Pauling resumed research on the topic. He c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Triphosphate
Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer. When consumed in metabolic processes, it converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP. The human body recycles its own body weight equivalent in ATP each day. It is also a precursor to DNA and RNA, and is used as a coenzyme. From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base ( adenine), the sugar ribose, and the triphosphate. Structure ATP consists of an adenine attached by the 9-nitrogen atom to the 1′ carbon atom of a sugar ( ribose), which in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Phosphorylation
Protein phosphorylation is a reversible post-translational modification of proteins in which an amino acid residue is phosphorylated by a protein kinase by the addition of a covalently bound phosphate group. Phosphorylation alters the structural conformation of a protein, causing it to become either activated or deactivated, or otherwise modifying its function. Approximately 13000 human proteins have sites that are phosphorylated. The reverse reaction of phosphorylation is called dephosphorylation, and is catalyzed by protein phosphatases. Protein kinases and phosphatases work independently and in a balance to regulate the function of proteins. The amino acids most commonly phosphorylated are serine, threonine, tyrosine in eukaryotes, and also histidine in prokaryotes and plants (though it is now known to be common in humans). These phosphorylations play important and well-characterized roles in signaling pathways and metabolism. However, other amino acids can also be phospho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinase
In biochemistry, a kinase () is an enzyme that catalysis, catalyzes the transfer of phosphate groups from High-energy phosphate, high-energy, phosphate-donating molecules to specific Substrate (biochemistry), substrates. This process is known as phosphorylation, where the high-energy adenosine triphosphate, ATP molecule donates a phosphate group to the substrate (biology), substrate molecule. This transesterification produces a phosphorylated substrate and Adenosine diphosphate, ADP. Conversely, it is referred to as dephosphorylation when the phosphorylated substrate donates a phosphate group and adenosine diphosphate, ADP gains a phosphate group (producing a dephosphorylated substrate and the high energy molecule of ATP). These two processes, phosphorylation and dephosphorylation, occur four times during glycolysis. Kinases are part of the larger family of phosphotransferases. Kinases should not be confused with phosphorylases, which catalyze the addition of inorganic phosphate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinase Wiki
In biochemistry, a kinase () is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule donates a phosphate group to the substrate molecule. This transesterification produces a phosphorylated substrate and ADP. Conversely, it is referred to as dephosphorylation when the phosphorylated substrate donates a phosphate group and ADP gains a phosphate group (producing a dephosphorylated substrate and the high energy molecule of ATP). These two processes, phosphorylation and dephosphorylation, occur four times during glycolysis. Kinases are part of the larger family of phosphotransferases. Kinases should not be confused with phosphorylases, which catalyze the addition of inorganic phosphate groups to an acceptor, nor with phosphatases, which remove phosphate groups (dephosphorylation). The phosphorylation state of a molecule, wheth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Helix
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues earlier along the protein sequence. The alpha helix is also called a classic Pauling–Corey–Branson α-helix. The name 3.613-helix is also used for this type of helix, denoting the average number of residues per helical turn, with 13 atoms being involved in the ring formed by the hydrogen bond. Among types of local structure in proteins, the α-helix is the most extreme and the most predictable from sequence, as well as the most prevalent. Discovery In the early 1930s, William Astbury showed that there were drastic changes in the X-ray fiber diffraction of moist wool or hair fibers upon significant stretching. The data suggested that the unstretched fibers had a coiled molecular structure with a characteristic repeat of ≈. Astbu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figure 1
Figure 1 is a Toronto, Ontario-based online social networking service for healthcare professionals to post and comment on medical images. Figure 1 was founded in Toronto by Dr. Joshua Landy, Richard Penner and Gregory Levey. The platform launched in North America in May 2013 and is now available in more than 100 countries. The privately held company reports more than 1 million healthcare professionals use its app and website. Funding In 2013, Figure 1 launched with $2 million (CDN) in seed money, with Rho Canada Ventures and Version One Ventures led the investment. In 2015, the company added $5 million (USD) to its Series A financing round, which was led by Union Square Ventures, an early investor in Twitter, Tumblr, Etsy, and Kickstarter. This brings the total round to $9 million (USD). Reception Figure 1's content has been characterized as "gruesome". The app's founder said the "very colorful images" are what medics see every day. "It's a transparent view into a world y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Barrel
In protein structures, a beta barrel is a beta sheet composed of tandem repeats that twists and coils to form a closed toroidal structure in which the first strand is bonded to the last strand (hydrogen bond). Beta-strands in many beta-barrels are arranged in an antiparallel fashion. Beta barrel structures are named for resemblance to the barrels used to contain liquids. Most of them are water-soluble proteins and frequently bind hydrophobic ligands in the barrel center, as in lipocalins. Others span cell membranes and are commonly found in porins. Porin-like barrel structures are encoded by as many as 2–3% of the genes in Gram-negative bacteria. It has been shown that more than 600 proteins with various function (e.g., oxidase, dismutase, amylase) contain the beta barrel structure. In many cases, the strands contain alternating polar and non-polar (hydrophilic and hydrophobic) amino acids, so that the hydrophobic residues are oriented into the interior of the barrel to form a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
