scholarly journals Three-dimensional structure of recombinant type 1 inositol 1,4,5-trisphosphate receptor

2010 ◽  
Vol 428 (3) ◽  
pp. 483-489 ◽  
Author(s):  
Francis Wolfram ◽  
Edward Morris ◽  
Colin W. Taylor
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Structural Basis ◽  
Particle Analysis ◽  
Three Dimensional Structure ◽  
Recombinant Type ◽  
Inositol 1,4,5 Trisphosphate ◽  
The Many ◽  
Trisphosphate Receptor

IP3Rs (inositol 1,4,5-trisphosphate receptors) are the intracellular channels that mediate release of Ca2+ from the endoplasmic reticulum in response to the many stimuli that evoke Ins(1,4,5)P3 formation. We characterized and purified type 1 IP3R heterologously expressed in Sf9 insect cells, and used the purified IP3R1 to determine its three-dimensional structure by electron microscopy and single-particle analysis. Recombinant IP3R1 has 4-fold symmetry with overall dimensions of approx. 19.5 nm×19.5 nm×17.5 nm. It comprises a small domain, which is likely to include the pore, linked by slender bridges to a large cytoplasmic domain with four petal-like regions. Our structures of recombinant IP3R1 and native cerebellar IP3R have similar appearances and dimensions. The only notable difference is the absence of a central stigma-like domain from the cytoplasmic region of recombinant IP3R1. The first structure of a recombinant IP3R is an important step towards developing three-dimensional structures of IP3R that better contribute to our understanding of the structural basis of IP3R activation.

scholarly journals Three-dimensional structure of a mouse-adapted type 2/type 1 poliovirus chimera.

1991 ◽  
Vol 10 (9) ◽  
pp. 2331-2341 ◽  
Author(s):  
T.O. Yeates ◽  
D.H. Jacobson ◽  
A. Martin ◽  
C. Wychowski ◽  
M. Girard ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Three Dimensional Structure

scholarly journals Location of the Permeation Pathway in the Recombinant Type 1 Inositol 1,4,5-Trisphosphate Receptor

1999 ◽  
Vol 114 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Josefina Ramos-Franco ◽  
Daniel Galvan ◽  
Gregory A. Mignery ◽  
Michael Fill
Keyword(s):  
Lipid Bilayers ◽  
Mammalian Cells ◽  
Single Channel ◽  
Site Directed Mutagenesis ◽  
Recombinant Type ◽  
Mutation Strategy ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor ◽  
Permeation Properties

The inositol 1,4,5-trisphosphate receptor (InsP3R) forms ligand-regulated intracellular Ca2+ release channels in the endoplasmic reticulum of all mammalian cells. The InsP3R has been suggested to have six transmembrane regions (TMRs) near its carboxyl terminus. A TMR-deletion mutation strategy was applied to define the location of the InsP3R pore. Mutant InsP3Rs were expressed in COS-1 cells and single channel function was defined in planar lipid bilayers. Mutants having the fifth and sixth TMR (and the interceding lumenal loop), but missing all other TMRs, formed channels with permeation properties similar to wild-type channels (gCs = 284; gCa = 60 pS; PCa/PCs = 6.3). These mutant channels bound InsP3, but ligand occupancy did not regulate the constitutively open pore (Po > 0.80). We propose that a region of 191 amino acids (including the fifth and sixth TMR, residues 2398–2589) near the COOH terminus of the protein forms the InsP3R pore. Further, we have produced a constitutively open InsP3R pore mutant that is ideal for future site-directed mutagenesis studies of the structure–function relationships that define Ca2+ permeation through the InsP3R channel.

Three-dimensional Structure of the Human Immunodeficiency Virus Type 1 Matrix Protein

1994 ◽  
Vol 244 (2) ◽  
pp. 198-223 ◽  
Author(s):  
Michael A. Massiah ◽  
Mary R. Starich ◽  
Chiana Paschall ◽  
Michael F. Summers ◽  
Allyson M. Christensen ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Matrix Protein ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Three Dimensional Structure ◽  
Immunodeficiency Virus

scholarly journals SERIAL RECONSTRUCTION OF THE CHARACTERISTIC GRANULE OF THE LANGERHANS CELL

1968 ◽  
Vol 36 (3) ◽  
pp. 595-602 ◽  
Author(s):  
Richard W. Sagebiel ◽  
Thomas H. Reed
Keyword(s):  
Electron Microscope ◽  
Electron Micrographs ◽  
Three Dimensional ◽  
Langerhans Cell ◽  
Human Epidermis ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Three Dimensional Structure ◽  
Three Dimensional Models ◽  
The Many

Three-dimensional models of individual granules in the same Langerhans cell were made after analyzing serial sections of human epidermis in the electron microscope. These models revealed that the granule is made up of a flattened or curved orthogonal net of particles which is bounded externally by a limiting membrane and which may be disc-shaped, cup-shaped, or combinations of both shapes. This variety of shapes accounts for the many configurations of the granule seen in individual electron micrographs. Usually, the granule has a vesicular portion at, or near one margin. This demonstration of the three-dimensional structure of the granule establishes the inaccuracy of previously used descriptive terms, the granule should be called simply the "Langerhans cell granule."

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