Nuclear Protein Membrane Essay, Research Paper
1. The nuclear envelope is a double membrane extension of the rough endoplasmic reticulum containing many nuclear pore complexes. The lipid bilayer of the inner nuclear membrane is supported by the nuclear lamina,a mesh work of lamin filament located adjacent to the inside face of the nuclear envelope.(Lodish et al 1997) The lamina is proposed to be involved in both organizing chromatin and in DNA replication in interphase cells (Gerace and Burke, 1988). Localization and isolation of nuclear lamina done by Nancy Dwyer and Gunter Blobel that nuclear lamina is indeed associated to fractional equivalent of a peripheral layer beneath the inner membrane of the nuclear envelope. Lamin was not attributed to residual DNAase resistant heterochromatin, there was no DNA nor histone proteins observed in chromatographic assays of the membrane-nuclear-pore-lamin layers.(Blobel and Dwyer, 1976). In addition, utilizing electron microscopy, membrane portions cut perpendicular to the nuclear membrane surface have shown that the nuclear lamina layer is submembranous as opposed to intramembranous. Nuclear lamin is a type of intermediate filament protein which are divided into two major subgroups. One subgroup contains NL-A and NL-C which are soluble’ during cell division, whereas the other contains NL-B proteins which remain associated with lipid vesicles during mitosis( Nigg 1992 as cited in Goldman et al 1992). How can one devise/design and experiment which determines the intracellular route(pathway) by which nuclear laminin is targeted to the inner face of the nuclear membrane? Nuclear lamin like all nuclear proteins are constructs including sequences encoding for a nuclear localization signal sequence(NLS). First in order to determine whether or not lamins are indeed localized in the nucleus, it can be ascertained by modifying or deleting the NLS to insure whether or not lamin assembly in the nucleas was obtained. This can be obtained by cloning lamin B from whole ovary mRNA by RT-PCR. Afterwards creating mutants using PCR, and then sub-cloning the relevant sequences into pGEX-4T-3.( Ellis et al). These mutants are immunolabelled using fluorescein or maybe gold-conjugated anti-lamin antibodies. The lamins are then added to egg extracts prior to sperm pronuclear assembly. Observations should show that these mutated lamins fail to polymerize within the nuclear membrane. These experiments are conducted with a control lamin which should support nuclear lamina assembly. Lamin incorporation during the interphase stage of the cell cycle can also be observed. Recent experiments have traced the pathway of incorporation of microinjected lamin A into the Nuclear Envelope. By obtaining human NL-A through the expression of the appropriate cDNA and then immunolabelling them through biotinylation followed by microinjecting the lamins in the cytosol of 3T3 cells, antibiotin and then antilamin antibodies conjugated with flourescein were used to detect where staining occurred. These cells were contrasted with cells not microinjected and just labelled with flourescein conjugated anti-lamins to show that the microinjected lamins are indeed incorporated into the same area with the same ability to integrate within the nuclear lamina network. Observations also show that the nuclear lamin network in mouse 3T3 cells are capable of incorporating new NL into its constituent polymeric structure during interphase (Goldman et al 1992).
Following the above experiments, it can be observed that lamins are targeted to the nucleus and the inner membrane layer of the nuclear envelope. How can it be shown that the targetted lamins are indeed incorporated to the inner face of the inner layer of the nucleus? An experiment using a cell-free nuclear assembly extract derived from Xenopus eggs show that three components are needed for successful nuclear envelope formation. These three components consist of membranes, nuclear pores and a nuclear lamina. By taking fractionated nuclear extracts and adding them to a soluble solution containing sperm chromatin, metaphase chromosome, or DNA, intact nuclear envelopes begin to form. Addition of lamins to nuclear membrane components without chromatin do not initiate nuclear envelope formation, neither does lamin addition to chromatin alone. By depleting the lamin content in a cell free system does not prevent nuclear envelope formation but severely handicaps both its size and ability to replicate DNA. This was observed by monitoring the rate of incorporation of radiolabeled dCTP into DNA assembled int o nuclei. By blocking nuclear protein transport using lectin WGA it is shown through immunoflourescence that a protein lamin layer is not formed within the nucleus although nuclear envelope formation(including nuclear pores) is not blocked. By counteracting the effect of WGA, lamin polymerization in the nucleus can is then restored. The results show that lamin incorporation may not occur until an intact, actively transporting nuclear envelope has formed around chromatin(Newport et al 1990). The results show that a receptor, like a lamin B receptor proposed to be located in the inner nuclear membrane and an intact nuclear envelope capable of selective nuclear transport surrounding chromatin are needed for lamin assembly showing that lamin are targetted to the nucleus and specifically to the inner face of the nuclear membrane.1. Blobel, G., Dwyer, N., A Modified procedure for the isolation of a pore complex-lamina fraction from Rat Liver nuclei. J. Cell Biology. Vol 70, 1976 581-591.2. Burke, B., Gerace, L., Cell free system to study reassembly of the nuclear envelope at the end of mitosis. Cell Vol 44 February 28, 1986 639-652.3. Ellis, D.J., Jenkins, H., Hutchison, C.J., Whitfield, W.G., GST-lamin fusion proteins act as dominant negative mutants in Xenopus egg extract and reveal the function of the lamina in DNA replication. J. Cell Science. Vol 110 October 7,1997, 2507-2518.4. Goldman, R.D., Goldman, J.E., Moir, R.D., Montag-Lowy, M., Stewart, M. Pathway of Incorporation of Microinjected Lamin A into the Nuclear Envelope. J.Cell Biology, Vol 119, Number 4, November 1992, 725-734.5. Lodish, H, Baltimore, D, Berk, A, Matsudaira, P, Darnell, J, Zipursky, L., Molecular Cell Biology, New York: Scientific American Books, 1997.6. Newport, J.W., Dunphy, W.,G., Wilson, K.L. A Lamin-independent Pathway for Nuclear Envelope Assembly., J. Cell Biology, Vol 111, 2247-2259
Другие работы по теме:
Current Research On Duchenne
’s Muscular Dystrophy Essay, Research Paper Duchenne’s muscular dystrophy is the result of a defective gene on the X chromosome. This gene is responsible for production of the muscle protein dystrophin.
Research In Biochemistry Essay Research Paper Angela
Research In Biochemistry Essay, Research Paper Angela LucasBiochemistry 3334/16/99Tullberg, A., Hakansson, G., and H. Race. 1998. A protein tyrosine kinase of chloroplast thylakoid membranes phosphorylates light harvesting complex II proteins. Biochemical and Biophysical Research Communications 250: 617-622.
Nutrition Essay Research Paper Nutrition and Diet
Nutrition Essay, Research Paper Nutrition and Diet Project My average calorie intake per day was 1531.8. My caloric need per day was 3326. My intake is supposed to be way more than what it is. This is really surprising to me. The average percentage of carbohydrates, fat and protein is in the chart below. DAY FAT CARBS PROTEIN SUGAR1 20% 34% 20% 25%2 10% 73% 17% 0%3 21% 47% 13% 19%4 18% 52% 15% 16%5 20% 48% 17% 15% These numbers are around what I should have.
Nuclear Power Plants Essay Research Paper Nuclear
Nuclear Power Plants Essay, Research Paper Nuclear Plants The question of whether the U.S. should have nuclear power plants is very controversial. There are two sides that one can take; however, both sides have their own share of problems. If you chose to not have nuclear plants, then eventually all natural resources will run out.
Explain With Aid Of A Diagram The
Working Of The Electron Microscope Essay, Research Paper The diagram below shows a picture of an electron microscope. This is a type of microscope that makes use of a
Nuclear Medicine Essay Research Paper Nuclear MedicineThere
Nuclear Medicine Essay, Research Paper Nuclear Medicine There are many things to be said about Nuclear Medicine. During the 20th century the world has seen many changes in medicine. One of the most ingenious creations of the century in the health field is Nuclear Medicine and Radiology. It is easily argued that modern medicine is the greatest accomplishment in human history1.
Nuclear Terrorism Essay Research Paper Today the
Nuclear Terrorism Essay, Research Paper Today, the terrorists have innumerable opportunities to attack where they want and also, how they want. The reason? Nobody knows, but how would you like if you would be able to put some nuclear stuff in a small box instead of looking for a place where you could drive your wagon full of explosives.
Antibiotics Essay Research Paper 46 Antibiotics
Antibiotics Essay, Research Paper 46. Antibiotics Antibiotics are chemical compounds used to kill or inhibit the growth of infectious organisms. Originally the term antibiotic referred only to organic compounds, produced by bacteria or molds, that are toxic to other microorganisms. The term is now used loosely to include synthetic and semisynthetic organic compounds.
Proteins Essay Research Paper Two Animal Products
Proteins Essay, Research Paper Two Animal Products vs. Two Protein Amino Acid Supplements The Protein and Amino Acid supplement make claims to build lean muscle mass in conjunction with a healthy diet and exercise (especially weight training). Protein and Amino Acid supplement companies advocate eating 6-8 small healthy meals a day which allows the body to use food more efficiently throughout the day for increased energy and performance.
Nucelar Enargy Essay Research Paper nuclear reactornuclear
Nucelar Enargy Essay, Research Paper nuclear reactor nuclear reactor, device for producing NUCLEAR ENERGY by controlled nuclear reactions. It can be used for either research or power production. The reactor is so constructed that the fission of atomic nuclei produces a self-sustaining nuclear chain reaction, in which the produced neutrons are able to split other nuclei.
Emergence Of The Nuclear Age Essay Research
Paper Emergence of the Nuclear Age I feel the most important issue which I learned in class was of the emergence of the nuclear age. I feel that this is important due to the fact
Nuclear Weapons Essay Research Paper The topic
Nuclear Weapons Essay, Research Paper The topic of nuclear weapons is one that will be around forever. One of my favorite lines from the reading we had was that we cannot uninvent nuclear
The Membrane Essay Research Paper The MembraneThe
The Membrane Essay, Research Paper The Membrane The membrane has a double lipid layer through which fat- soluble substances will move, by passive transport or diffusion. The molecules will only move through if they are small enough.
Bacteria Essay Research Paper True cells
Bacteria Essay, Research Paper True cells with a wall, membrane, cytoplasm, ribosomes and DNA. No distinct nucleus DNA not incorporated in chromosomes but comprising a single, circular strand Bacteria
Bignerds Essay Research Paper Why nuclear fusion
Bignerds Essay, Research Paper Why nuclear fusion is so cool……. For a fusion reaction to take place, the nuclei, which are positively charged, must have enough kinetic energy to overcome their electrostatic force of repulsion. This can occur either when one nucleus is accelerated to high energies by an accelerating device, or …
The Nervous System Diagnosed Essay Research Paper
outside the central nervous system. Understanding how the neurons work is vital to understanding the nervous system. Neurons The neuron has two important structures called the dendrite and axon, also called nerve fibers. The dendrites are like tentacles that sprout from the cell and the axon is one long extension of the cell.
Cells Essay Research Paper CellsCells are the
Cells Essay, Research Paper Cells Cells are the basic unit of all life. Even though they are the smallest unit of life they are highly complex. Each cell has enough parts to it to
BioReport Essay Research Paper 1 Cellular TransportaOsmosisOsmosis
Bio-Report Essay, Research Paper 1.) Cellular Transport a.Osmosis Osmosis is the diffusion of water molecules across a differentially permeable membrane from a region where water molecules are more concentrated to one where they are less concentrated. The transport of water is simple the cell being selectively permeable will allow water through it until an equilibrium is reached and at that time water will flow both in and out of the cell maintaining the equilibrium.
Atp Production Essay Research Paper ATP ProductionMetabolism
Atp Production Essay, Research Paper ATP Production Metabolism, which encompasses glycolysis, the Kreb s cycle, and the electron transport system, occurs in the mitochondria of cells. The mitochondria consist of a double membrane and an inner compartmentalization called the matrix. Each of the processes of metabolism occurs in specific locations in and around the mitochondria.
High Protein Essay Research Paper A high
High Protein Essay, Research Paper A high protein diet is essentially that, a diet that is high in protein. However… The diet is not only high in protein, but it is low in other nutrients
Virii Essay Research Paper Viruses are
Virii Essay, Research Paper Viruses are not truly alive. They are much smaller and less complex than cells. Most viruses multiply exclusively inside living host cells. Viruses
Mitosis Meiosis Essay Research Paper Mitosis evolved
Mitosis Meiosis Essay, Research Paper Mitosis evolved in complex plants and animals for growth and repair. Mitosis, the division of a cell resulting in two identical daughter cells, prolongs an organism s life by
Protein Synthesis Essay Research Paper Understanding Human
Protein Synthesis Essay, Research Paper Understanding Human Genetics: From Nucleotides to Life Within the nuclei of every one of our cells lie massive amounts of information. This information is stored neatly in our chromosomes. The coding on these chromosomes dictates every aspect of our physical self, but it is useless if it simply remains undecoded in the depths of our nuclei; it must be translated into something that can be read.
Cells Essay Research Paper NucleusCell WallCell Membrane
Cells Essay, Research Paper Nucleus Cell Wall Cell Membrane Ribosome Mitochondria Vacuoles Nucleolus Endoplasmic Reticulm Lysosomes 5. Have the “cell membrane people” cut the large piece of plastic wrap in half and place each
Nuclear Energy Essay Research Paper Nuclear Energy
Nuclear Energy Essay, Research Paper Nuclear Energy should be produced because it is an alternative to fossil fuel. Nuclear energy helps to conserve our national resources that we use as fuel such as coil, oil, and natural gas. Another pro of nuclear energy is that radiation that is given off by nuclear energy is mostly thought of a very dangerous thing but it can be used in positive ways too.
Diet Macronutrients Essay Research Paper My diet
Diet Macronutrients Essay, Research Paper My diet is acceptable in the following Macronutrients: dairy group (3 servings), vegetable soup (3 servings), fruit group (4 servings), and starch/grain (7
Zone Dieting Essay Research Paper ZONE DIETINGProtein
Zone Dieting Essay, Research Paper ?ZONE? DIETING Protein, protein, protein-that?s all I hear at my 24 hours gym. I thought that people in my gym talked about it because protein is what you need to take in order to build muscles. However, people used those proteins to lose weight. I was astonished about this ?ZONE? dieting.
Osmosis 2 Essay Research Paper Osmosis in
Osmosis 2 Essay, Research Paper Osmosis, in botany and chemistry, the flow of one constituent of a solution through a membrane while the other constituents are blocked and unable to pass through the membrane. Experimentation is necessary to determine which membranes permit selective flow, or osmosis, because not all membranes act in this way.
Protein Synthesis Essay Research Paper Protein Synthesis
Protein Synthesis Essay, Research Paper Protein Synthesis Protein synthesis is the process by which genetic information from the DNA stored in the nucleus is transferred to the ribosomes where it is used to arrange amino acids into proteins.
Cell Membrane Electron Transport Chain Biochemical
Pathway Essay, Research Paper 1. The cell membrane structure is vital to the life of the cell. The cell membrane is shaped as having a phosphate head at the very outer surface, and two fatty acid tails hanging from it. The membrane is double, so at the tip of the fatty acid tails, there are two more fatty acid tails attached to another phosphate head.
Animal Cell Essay Research Paper Animal CellThe
Animal Cell Essay, Research Paper Animal CellThe model cell that you are looking at is an animal cell. The model is labeled with all of the typical organelles within a cell membrane. The following words are parts of the cell structure and the different jobs each one performs:Cell Membrane- phospholipid-protein bilayer; separates cell content from the environment.
Cell Structure Definitions Essay Research Paper DefinitionsCell
Cell Structure Definitions Essay, Research Paper Definitions: Cell Wall A structure made of cellulose that is, in the plant, responsible for many tasks. Firstly, it maintains the shape of the cell, and secondly it protects the cell from external forces. It also serves as a connector between the cell in question and its neighboring cells.
Plant Cell Essay Research Paper I am
Plant Cell Essay, Research Paper I am your usual plant cell. There are trillions of my kind on all plants, grass, and trees. My breed ranges from ten to a hundred micrometers. I am approximately twenty micrometers since I dwell in grass. My organelles stretch out to one to ten micrometers. If you are asking what I really do and how I live, I am going to answer them in this paper.
Gene Mutation Essay Research Paper Define Gene
Gene Mutation Essay, Research Paper Define Gene Mutation A change in the base sequence of a gene Outline the difference between an insertion and a deletion Explain the consequence of a base substitution mutation in relation to the