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Post by skyship on Mar 13, 2010 13:42:21 GMT -5
Secondary structures: The folding of proteins in vivo and in vitro? Folding leads to the structure of the protein. The result of misfolding can lead to commonly know gene mutuation and diseases - Alzheimer's, cystic fibrosis, osteogensis imperfecta, ... The further study of protein folding has lead to a new understand of transmission of some dieases. The primary protein structure is when amino acids bond creating a chain. The next stage is the secondary structure which are often found in 2 possible forms: alpha helix and beta pleated sheet. There are other forms in a simply folded structure. The tertiary structure (3-d structure) it the one that give the protein it's overall shape. The structures continue on into quaternary and others. activecampus.org/cm02/content/foldingskyship
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Post by lilsissy on Mar 14, 2010 4:20:10 GMT -5
G.F.P. is folded too.
Jen
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Post by skyship on Mar 14, 2010 8:10:50 GMT -5
Wonder if it is called green flourescent prion? Durn shootin! Internalization of mammalian fluorescent cellular prion protein and N-terminal deletion mutants in living cellsKEYWORDS copper metabolism • endocytosis • glycosylphosphatydilinositol anchored protein • green fluorescent protein • prion • SN56 cells ABSTRACT The cellular prion protein (PrPc) is a glycosylphosphatidylinositol (GPI)-anchored plasma membrane protein whose conformational altered forms (PrPsc) are known to cause neurodegenerative diseases in mammals. In order to investigate the intracellular traffic of mammalian PrPc in living cells, we have generated a green fluorescent protein (GFP) tagged version of PrPc. The recombinant protein was properly anchored at the cell surface and its distribution pattern was similar to that of the endogenous PrPc, with labeling at the plasma membrane and in an intracellular perinuclear compartment. Comparison of the steady-state distribution of GFP-PrPc and two N-terminal deletion mutants (Δ32-121 and Δ32-134), that cause neurological symptoms when expressed in PrP knockout mice, was carried out. The mutant proteins accumulated in the plasma membrane at the expense of decreased labeling in the perinuclear region when compared with GFP-PrPc. In addition, GFP-PrPc, but not the two mutants, internalized from the plasma membrane in response to Cu2+ treatment and accumulated at a perinuclear region in SN56 cells. Our data suggest that GFP-PrPc can be used to follow constitutive and induced PrPc traffic in living cells. Resubmitted manuscript received June 29, 2001; accepted July 11, 2001. mammalianwww3.interscience.wiley.com/journal/120707122/abstract?CRETRY=1&SRETRY=0We are nailin em! ======== It is mutant and it is SELECTIVE!
"Instead, mutant PrPs trafficked to the Golgi, from where the misfolded subpopulation was selectively trafficked for degradation in acidic compartments. Surprisingly, selective re-routing was dependent not only on a mutant globular domain, but on an additional lysine-based motif in the highly conserved unstructured N-terminus. These results define a specific trafficking and degradation pathway shared by many disease-causing PrP mutants. As the acidic lysosomal environment has been implicated in facilitating the conversion of PrPC to PrPSc, our identification of a mutant-selective trafficking pathway to this compartment may provide a cell biological basis for spontaneous generation of PrPSc in familial prion disease.
www.plospathogens.org/article/info:doi%2F10.1371%2Fjournal.ppat.1000479
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Circularly permuted green fluorescent proteins engineered to sense Ca2+ Takeharu Nagai, Asako Sawano, Eun Sun Park, and Atsushi Miyawaki*
Abstract To visualize Ca2+-dependent protein–protein interactions in living cells by fluorescence readouts, we used a circularly permuted green fluorescent protein (cpGFP), in which the amino and carboxyl portions had been interchanged and reconnected by a short spacer between the original termini. The cpGFP was fused to calmodulin and its target peptide, M13. The chimeric protein, which we have named “pericam,” was fluorescent and its spectral properties changed reversibly with the amount of Ca2+, probably because of the interaction between calmodulin and M13 leading to an alteration of the environment surrounding the chromophore. Three types of pericam were obtained by mutating several amino acids adjacent to the chromophore. Of these, “flash-pericam” became brighter with Ca2+, whereas “inverse-pericam” dimmed. On the other hand, “ratiometric-pericam” had an excitation wavelength changing in a Ca2+-dependent manner. All of the pericams expressed in HeLa cells were able to monitor free Ca2+ dynamics, such as Ca2+ oscillations in the cytosol and the nucleus. Ca2+ imaging using high-speed confocal line-scanning microscopy and a flash-pericam allowed to detect the free propagation of Ca2+ ions across the nuclear envelope. Then, free Ca2+ concentrations in the nucleus and mitochondria were simultaneously measured by using ratiometric-pericams having appropriate localization signals, revealing that extra-mitochondrial Ca2+ transients caused rapid changes in the concentration of mitochondrial Ca2+. Finally, a “split-pericam” was made by deleting the linker in the flash-pericam. The Ca2+-dependent interaction between calmodulin and M13 in HeLa cells was monitored by the association of the two halves of GFP, neither of which was fluorescent by itself.
www.ncbi.nlm.nih.gov/pmc/articles/PMC30630/
THERE IS THE M13
Here looks like using GFP to find the prions and where they fold!
skyship
skyship
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Post by skyship on Mar 14, 2010 9:08:57 GMT -5
extra-mitochondrial Ca2+ transients caused rapid changes in the concentration of mitochondrial Ca2+. Finally, a “split-pericam” was made by deleting the linker in the flash-pericam. The Ca2+-dependent interaction between calmodulin and M13 in HeLa cells was monitored by the association of the two halves of GFP, neither of which was fluorescent by itself. Mitochondrial Ca2+ seems to show up in the Pancreas stuff! Abstract Mitochondrial Ca2+ homeostasis is today at the center of wide interest in the scientific community because of its role both in the modulation of numerous physiological responses and because of its involvement in cell death. In this review, we briefly summarize a few basic features of mitochondrial Ca2+ handling in vitro and within living cells, and its involvement in the modulation of Ca2+-dependent signaling. We then discuss the role of mitochondrial Ca2+ in the control of apoptotic death, focusing in particular on the effects of pro- and anti-apoptotic proteins of the Bcl-2 family. Finally, the potential involvement of Ca2+ and mitochondria in the development of two diseases, Ullrich muscular dystrophy and familial Alzheimer's disease, is briefly discussed. www.nature.com/cdd/journal/v14/n7/full/4402147a.html====== www.nature.com/cdd/journal/v14/n7/fig_tab/4402147f2.html#figure-titleUniporter VDAC: "It's now safe to say that the mitochondrial calcium uniporter is an ion channel. Interestingly enough, this is the only known intracellular calcium-selective channel." --Yuriy Kirichok "In people, calcium floods into cells' cytoplasmic soup for many precisely timed functions. When a sperm fertilizes an egg, a calcium wave signals the embryo to develop. Calcium makes muscle cells contract, including for each heart beat. In nerves, it controls neurotransmitter release." focus.hms.harvard.edu/2004/feb6_2004/cell_biology.html The ca2+ is involved in the the excessive calcium involved in the pancreas I think too. ========== HUMAN DISEASES ASSOCIATED WITH TRANSPORTERS www.tcdb.org/disease_explore.phpIn agreement, maxi-K channels are activated by nitrocompounds (16), probably through a PKG-dependent phosphorylation mechanism (14, 17, 18). Two main mechanisms have been proposed to explain the activation of native maxi-K channels by PKG. One mechanism suggests that PKG activates maxi-K channels through a direct phosphorylation of the channel protein or a regulatory subunit (17, 19–21); this process can be reversed by phosphatase 2A (22). In contrast, the second mechanism proposes that PKG activates maxi-K channels indirectly via a PKG-dependent activation of protein phosphatase 2A (23, 24), which may directly dephosphorylate maxi-K channels. Alternatively, protein phosphatase 2A may exert its effect indirectly. www.anes.ucla.edu/~ltoro/PAPERS/JBC98-LT-PKG.pdfthe smooth muscle, phosphorylation and dephosphorylation is involved here. skyship
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Post by aqt on Mar 14, 2010 11:01:12 GMT -5
phosphorylation?
knew we'd come back to that one...
aqt
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