The membrane of various cells throughout the body hold CFTR protein channels, which control the transport of ions in and out of the cells to sustain pH homeostasis, electrically charged chloride ions (salt) levels, and fluid levels within epithelial tissues. Akabas (2000) describes the CFTR as an ATP-binding cassette (ABC) membrane transporter gene. There are 1480 amino acids producing two halves connected by the cytoplasmic regulatory domain (R-domain). The two halves create channels that allow negatively charged chloride ions to travel out of the cell (Thomson and Harris, 2008). As demonstrated in the above diagram, the channel extends from extracellular area through the cell membrane and narrows at the charge selective filter as it enters the cytoplasm within the cell, finishing after the attachment of the anion binding site (Hwang & Sheppard, 2009). Figure 3 demonstrates how the CFTR is assembled of five domains; two membrane-spanning domains (MSDs) are purple and green, two nucleotide-binding domains (NBDs) blue and green, and a unique regulatory domain (RD) red (Hwang & Sheppard, 2009). Recent research by Hwang and Sheppard (2009) explains that MSDs form the low conductance anion selective pore. Selecting for only chloride ions to exit the cell. Gadsby and Nairn (1999) explain that the R-domain is the site for phosphorylation. This is the prerequisite for opening the chloride channels and is the activity determining the level of CFTR activation. It controls the chloride ion transport. The more phosphorylation the higher the probability of the channel opening according to Akabas (2000). The multiple locations for phosphorylation include c-AMP dependent protein kinases (PKA), and protein kinase C (PKC) (Gadsby & Narin, 1... ... middle of paper ... ...sis/page3.htm Conrad, M. (2014). Cystic fibrosis. Retrieved from http://www.medicinenet.com/cystic_fibrosis/page3.htm Hwang, T., Sheppard, D. (2009). Conformational changes of the CFTR Cl− channel during channel gating Diagram. Retrieved from http://jp.physoc.org/content/587/10/2151.full Sequeriros, I., Jarad, N. (2012). Chest Radiograph Image. Retrieved from http://cdn.intechopen.com/pdfs-wm/34276.pdf Sequeriros, I., Jarad, N. (2012). Axial Lung CT Image. Retrieved from http://cdn.intechopen.com/pdfs-wm/34276.pdf Marieb, E., Hoehn, K. (2012). Human Anatomy & Physiology. McWilliams, T,. Wilsher,M,. Kolbe, J,. (2000). New Zealand Medical Journal. 133 (1102), 6-8. Retrieved from http://journal.nzma.org.nz/journal/113-1102/2202/content.pdf Welsh, M., Smith A. (1995). Cystic Fibrosis. Retrieved from https://www.msu.edu/~luckie/cfarticle.html
Cystic Fibrosis (CF) Pathophysiology: Cystic fibrosis is a genetic disease of the secretory glands that affects the respiratory and digestive system. It mainly affects the lungs, pancreas, liver, intestines, sinuses, and reproductive organs. Cystic fibrosis affects the cells that produce sweat, mucus, and digestive fluids. Mucus becomes thick and sticky, causing build-up in the lungs and blocking airways, making it easier for bacteria to develop. This prompts repeated lung infections and can cause severe lung damage after some time.
There are a series of nodes along the axon where there is a high concentration of sodium (Na+) and K+ channels. There is a high concentration of Na+ outside the cell and a high concentration of K+ inside the cell. As the nodes sen...
Being diagnosed with a chronic illness is a life-altering event. During this time, life is not only difficult for the patient, but also for their loved ones. Families must learn to cope together and to work out the best options for the patient and the rest of the family. Although it may not be fair at times, things may need to be centered on or around the patient no matter what the circumstance. (Abbott, 2003) Sacrifices may have to be made during difficult times. Many factors are involved when dealing with chronic illnesses. Coping with chronic illnesses alter many different emotions for the patients and the loved ones. Many changes occur that are very different and difficult to get used to. (Abbott, 2003) It is not easy for someone to sympathize with you when they haven’t been in the situation themselves. No matter how many books they read or people they talk to, they cannot come close to understanding.
This occurs when special carrier proteins carry solutes dissolved in the water across the membrane by using active transport. When the concentration gradient can not allow travel from one side of the membrane to the other fast enough for the cell’s nutritional needs, then facilitated diffusion is used. The transport protein is specialized for the solute it is carrying, just as enzymes are specialized for their substrate. The transport protein can be
c. Na+ and K+ gates are closed. Na+ are concentrated outside the cell; K+ are concentrated inside the cell.
...Journal." Canadian Medical Association Journal - March 8, 2011. 22 July 2003. Web. 08 Mar. 2011.
Modern molecular genetics has given hopes and heartaches to thousands of people around the world. These people are looking towards gene therapy for an answer to their questions. To some people such as NIH director Harold Varmus the answer is a better understanding of basic genetic research and to others the answer is a cure, a hope, that their lethal disease will someday be cured. This essay touches on the background of gene therapy for Cystic Fibrosis (CF), current social and ethical issues facing gene therapy for CF, and some thoughts on the importance of this controversial subject.
“The plasma membrane is the edge of life, the boundary that separates the living cell from its nonliving surroundings. The plasma membrane is a remarkable film, so thin that you would have to stack 8,000 of these membranes to equal the thickness of the page you are reading. Yet the plasma membrane can regulate the traffic of chemicals into and out of the cell. The key to how a membrane works is its structure” (Simon, 02/2012, p. 60).
Membranes play an integral function in trapping and securing metabolic products within the borders of a cell within an aqueous environment. Without a selectively permeable border surrounding sites of anabolic function, potential useful products of this metabolism would simply diffuse away in the aqueous environment contained within and surrounding the cell. However, securing metabolites within the cell also comes with a price of not being able to acquire potentially useful compounds from the surrounding environment. Some very small gases and polar uncharged compounds are able to simply diffuse across this membrane, moving to the site of lower concentration on either side of the membrane. However, larger uncharged and charged polar molecules,
Byrant et.al [1] notes that a rapid response is initiated by a ligand/drug binding to a receptor on the ligand gated channel on the cell surface. This binding of the ligand results in the ligand gated channel to open or close, triggering the entry or exit of ions into or out of the cell, along a concentration gradient, causing a cellular response the cell. [2]. Cocaine is an example of a drug which blocks sodium channels. This causes blocked neural transmission and localized loss of sensation [3].
U.S. National Library of Medicine, 26 Sept. 2011. Web. The Web. The Web. 19 Nov. 2013.
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Turner, B. J., Newschaffer, C. J., Zhang, D., Fanning, T., & Hauck, W. W. (1999). Translating clinical trial results into practice. Annals of Internal Medicine, 130(12), 979-986.
If we examine the detailed structures of many transmembrane proteins, we see that they often have three different domains, two hydrophilic and one hydrophobic .(fig 1&2) A hydrophilic domain (consisting of hydrophilic amino acids) at the N-terminus pokes out in the extracellular medium, a hydrophobic domain in the middle of the amino acid chain, often only 20-30 amino acids long, is threaded through the plasma membrane, and a hydrophilic domain at the C-terminus protrudes into the cytoplasm. The transmembrane domain, because it is made of amino acids having hydrophobic side chains, exists comfortably in the hydrophobic inner layers of the plasma membrane. Because these transmembrane domains anchor many proteins in the lipid bilayer, these proteins are not free-floating and cannot be isolated and purified biochemically without first dissolving away the lipid bilayer with detergents. (Indeed, much of the washing we do in our lives is necessitated by the need to solubilize proteins that are embedded in lipid membranes using detergents!)
Ed. David Zieve. U.S. National Library of Medicine, 26 Feb. 2014. Web. The Web.