![]()
|
|
||||||||
J. Biol. Chem., Vol. 263, Issue 10, 4541-4548, Apr, 1988
G Guillemette, T Balla, AJ Baukal and KJ Catt
Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
The distribution of hepatic binding sites for the calcium-mobilizing second messenger, inositol 1,4,5-trisphosphate (IP3), was analyzed in subcellular fractions of the rat liver by binding studies with [32P]IP3 and compared with the Ca2+ release elicited by IP3 in each fraction. Three major subcellular fractions enriched in plasma membrane, mitochondria, and endoplasmic reticulum were characterized for their 5'- nucleotidase, glucose-6-phosphatase, succinate reductase, and angiotensin II binding activities. The fraction enriched in plasma membrane showed 7- and 20-fold increases in IP3 binding capacity over those enriched in endoplasmic reticulum and mitochondria, respectively, and contained a single class of high-affinity binding sites with Kd of 1.7 +/- 1.0 nM and concentration of 239 +/- 91 fmol/mg protein. IP3 binding reached equilibrium in 30 min at 0 degrees C, and the half-time of dissociation was about 15 min. The specificity of the IP3 binding sites was indicated by their markedly lower affinities for inositol 1- phosphate, phytic acid, fructose 1,6-bisphosphate, 2,3- bisphosphoglycerate, and inositol 1,3,4,5-tetrakisphosphate. The Ca2+- releasing activity of IP3 in the subcellular fractions was monitored with the fluorescent indicator, Fura-2. All three fractions showed ATP- dependent Ca2+ uptake and rapidly released Ca2+ in response in IP3. The fraction enriched in plasma membrane was the most active in this regard, releasing 174 +/- 67 pmol Ca2+/mg of protein compared to 45 +/- 10 and 48 +/- 7 pmol/mg protein for the fractions enriched in endoplasmic reticulum and mitochondria, respectively. These data suggest that the [32P]IP3 binding sites represent specific intracellular receptors through which IP3 mobilizes Ca2+ from a storage site associated (or co-purifying) with the plasma membrane of the rat liver. It is likely that a specialized vesicular system (to which IP3 can bind and trigger the release of Ca2+) is located in close proximity with the plasma membrane and is thus adjacent to the site at which IP3 is produced during stimulation of the hepatocyte by Ca2+-mobilizing hormones.
This article has been cited by other articles:
![]() |
P. Varnai, B. Toth, D. J. Toth, L. Hunyady, and T. Balla Visualization and Manipulation of Plasma Membrane-Endoplasmic Reticulum Contact Sites Indicates the Presence of Additional Molecular Components within the STIM1-Orai1 Complex J. Biol. Chem., October 5, 2007; 282(40): 29678 - 29690. [Abstract] [Full Text] [PDF] |
||||
![]() |
T Balla Phosphoinositide-derived messengers in endocrine signaling J. Endocrinol., February 1, 2006; 188(2): 135 - 153. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Zhang, A. Mizutani, C. Hisatsune, T. Higo, H. Bannai, T. Nakayama, M. Hattori, and K. Mikoshiba Protein 4.1N Is Required for Translocation of Inositol 1,4,5-Trisphosphate Receptor Type 1 to the Basolateral Membrane Domain in Polarized Madin-Darby Canine Kidney Cells J. Biol. Chem., January 31, 2003; 278(6): 4048 - 4056. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Guihard, J. Noel, and T. Capiod Ca2+ Depletion and Inositol 1,4,5-Trisphosphate-evoked Activation of Ca2+ Entry in Single Guinea Pig Hepatocytes J. Biol. Chem., April 28, 2000; 275(18): 13411 - 13414. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Ueda, S. Tamura, N. Fukushima, T. Katada, M. Ui, and M. Satoh Inositol 1,4,5-Trisphosphate-Gated Calcium Transport through Plasma Membranes in Nerve Terminals J. Neurosci., May 1, 1996; 16(9): 2891 - 2900. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Khan, J. Steiner, M. Klein, M. Schneider, and S. Snyder IP3 receptor: localization to plasma membrane of T cells and cocapping with the T cell receptor Science, August 7, 1992; 257(5071): 815 - 818. [Abstract] [PDF] |
||||
![]() |
A. Tanimura, Y. Tojyo, and R. J. Turner Evidence That Type I, II, and III Inositol 1,4,5-Trisphosphate Receptors Can Occur as Integral Plasma Membrane Proteins J. Biol. Chem., August 25, 2000; 275(35): 27488 - 27493. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |