http://thecellbiology.com/cellopedia/ Changes made in cellopedia are viewable here, in this page! en-us Monday, 06 Feb 2012 01:02:47 Monday, 06 Feb 2012 01:02:47 Cellopedia RSS Engine Cellopedia editors thecellbiology@gmail.com 5 http://thecellbiology.com/cellopedia/showdoc.aspx?name=EMT ==Introduction== [b]Epithelial Mesenchymal Transition[b] is a process in which epithelial cells lose epithelial characteristics like apico-basolateral polarity and adhesion to each other and instead they acquire mesenchymal traits like frontal-back polarity(also known as spindle shaped polarity) motility and secretion of various extracellular components like collagens, laminins and fibronectins in addition to a plethora of matrix metaloproteinases. ==Regulators== ===Transcription Factors=== Several key embryonic transcription factors is implicated in orchestrating this massive program. among these are Snail1, Snail2(Also called Slug), Twist, ZEB1/2, Goosecoid. ===Cytokines and Growth Factors=== EMT program is often initiated in response to specific cytokines like TGFBeta and TNFAlpha and several growth factors like EGF, PDGF and VEGF. [category:Cancer] 5/20/2010 8:40:00 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=p53 ==Introduction== {{p53 detail >>image, p53.png >>scale, .5 >>PDB id, [[pdb:1TUP]] >>Program, Pymol }} p53 is a transcription factor and also a tumor supressor protein. aberrant forms of this protein are found in numerous cancers. ===Li Fraumeni Syndrome=== One copy of normal p53 in germline leads to numerous tumor. this condition is called Li-Fraumeni syndrome. ===Regulation=== p53 is regulated by proteolytic mechanisms. upon binding to Mdm2, the protein is ubiquitinated and then degrades in proteosomes. phosphorylation by other factors prevent degradation of p53. [category:protein][category:cancer] 5/16/2010 6:24:50 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=EMT ==Introduction== [b]Epithelial Mesenchymal Transition[b] is a process in which epithelial cells lose epithelial characteristics like apico-basolateral polarity and adhesion to each other and instead they acquire mesenchymal traits like frontal-back polarity(also known as spindle shaped polarity) motility and secretion of various extracellular components like collagens, laminins and fibronectins in addition to a plethora of matrix metaloproteinases. ==Regulators== ===Transcription Factors=== Several key embryonic transcription factors is implicated in orchestrating this massive program. among these are Snail1, Snail2(Also called Slug), Twist, ZEB1/2, Goosecoid. ===Cytokines and Growth Factors=== EMT program is often initiated in response to specific cytokines line TGFBeta and TNFAlpha and several growth factors like EGF, PDGF and VEGF. [category:Cancer] 5/15/2010 8:56:26 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=EMT ==Introduction== [b]Epithelial Mesenchymal Transition[b] is a process in which epithelial cells lose epithelial characteristics like apico-basolateral polarity and adhesion to each other and instead they acquire mesenchymal traits like frontal-back polarity(also known as spindle shaped polarity) motility and secretion of various extracellular components like collagens, laminins and fibronectins in addition to a plethora of matrix metaloproteinases. ==Regulators== ===Transcription Factors=== Several key embryonic transcription factor is implicated in orchestrating this massice program. among these are Snail1, Snail2(Also called Slug), Twist, ZEB1/2, Goosecoid. ===Cytokines and Growth Factors=== EMT program is often initiated in response to specific cytokines line TGFBeta and TNFAlpha and several growth factors like EGF, PDGF and VEGF. [category:Cancer] 5/15/2010 8:54:15 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=EMT ==Introduction== [b]Epithelial Mesenchymal Transition[b] is process in which epithelial cells lose epithelial characteristics like apico-basolateral polarity and adhesion to each other and instead they acquire mesenchymal traits like frontal-back polarity(also known as spindle shaped polarity) motility and secretion of various extracellular components like collagens, laminins and fibronectis in addition to a plethora of matrix metaloproteinases. ==Regulators== ===Transcription Factors=== Several key embryonic transcription factor is implicated in orchestrating this massice program. among these are Snail1, Snail2(Also called Slug), Twist, ZEB1/2, Goosecoid. ===Cytokines and Growth Factors=== EMT program is often initiated in response to specific cytokines line TGFBeta and TNFAlpha and several growth factors like EGF, PDGF and VEGF. [category:Cancer] 5/15/2010 8:53:19 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=EMT ==Introduction== [b]Epithelial Mesenchymal Transition[b] is process in which epithelial cells lose epithelial characteristics like apico-basolateral polarity and adhesion to each other and instead they acquire mesenchymal traits like frontal-back polarity(also known as spindle shaped polarity) motility and secretion of various extracellular components like collagens, laminins and fibronectis in addition to a plethora of matrix metaloproteinases. [category:Cancer] 5/15/2010 8:48:55 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=EMT ==Introduction== [b]Epithelial Mesenchymal Transition[b] is process in which epithelial cells lose epithelial characteristics like apico-basolateral polarity and adhesion to each other and instead they acquire mesenchymal traits like frontal-back polarity(also known as spindle shaped polarity) motility and secretion of various extracellular components like collagens, laminins and fibronectis in addition to a plethora of matrix metaloproteinases. 5/15/2010 8:47:06 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=Calmodulin ==Introduction== {{Calmodulin info >>image,calmudulin-new.png >>scale,.4 >>PDB id,[[pdb:1UP5]] }} Calmodulin is a Ca binding protein. it consists of four so called EF hand motifs which provide a ASP containing framework to bind Ca ions. upon binding of the Ca the protein undergoes remarkable conformational changes. this changes provide a hydrophobic anchor site to bind other proteins and activating them. this activation leads to varying physiological responses based on activated protein. ===Calmodulin as a Ca regulator=== As we do know Ca concentration must be regulated in cytosol. this regulation occurs when high concentration of calcium is in cytosol. when cytosolic ca concentration increases it binds to calmodulin. in turn activated calmodulin makes contact with specific plasma membrane ca ion pump. this may lead to activation of the pump and subsequent ca concentration decrease in cytosol. ===smooth muscle activation=== activated calmodulin also induces smooth muscle contraction. calmodulin does this in two pathway: 1)Binding to specific protein called [b]caldesmon[b]. this protein when not bound to calmodulin, binds to [[actin]] filaments and inhibits muscle contraction. 2)activate a specifc [b]CaM Kinase[b] which phosphorylates light chain of myosin and activates myosin. {img >>src,calmudulin_Kinase.png >>desc,calmodulin in contact with a CaM Kinase(a portion) >>scale,.5 } [category:protein] 5/21/2009 5:05:28 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=Actin ==Inroduction== Actin, Microtubule and Intermediate Filaments constitute the cytoskeleton. These robust structures confer stability, motility and other characteristics to the cell. These elaborate protein structures are composed of protein monomers thus giving them the ability of dynamics. Actin filaments, also known as F-Actin is composed of Globular monomeric Actin protein(G-Actin). These monomers interact together via various non-covalent interactions to produce a filament which has a characteristic twist. Polymerization requires hydrolysation of monomer bound ATP to form an ADP. ==Structure== ===G Actin=== Globular Actin is monomeric form of actin. This protein is bounded with ATP. {img >>src,gactin.png>>scale,.3 >>desc,Monomeric globular Actin} ===F Actin=== Filament Actin has a characteristic twist every 13 monomers. {img >>src,factin.jpg >>scale,.3 >>desc,Filament Actin} ==Biological Filament Generation== ===ARP2/3 Complexes=== ARP2/3 is structurally similar to actin. This complex lies on side of a preexisting actin and initiate actin filament formation specially in leading edge assists cell locomotion. ===Formin Complexes=== [category:Protein] 5/17/2009 9:34:30 AM http://thecellbiology.com/cellopedia/showdoc.aspx?name=Actin ==Inroduction== Actin, Microtubule and Intermediate Filaments constitute the cytoskeleton. These robust structures confer stability, motility and other characteristics to the cell. These elaborate protein structures are composed of protein monomers thus giving them the ability of dynamics. Actin filaments, also known as F-Actin is composed of Globular monomeric Actin protein(G-Actin). These monomers interact together via various non-covalent interactions to produce a filament which has a characteristic twist. Polymerization requires hydrolysation of monomer bound ATP to form an ADP. {img >>src,gactin.png>>scale,.3 >>desc,Monomeric globular Actin} 5/17/2009 9:11:43 AM