|
|
|
|||||||
|
|||||||||
J Biol Chem, Vol. 274, Issue 42, 29858-29861, October 15, 1999
From the The tilapia fish Oreochromis alcalicus
grahami from Kenya has adapted to living in waters at pH 10.5 by
excreting the end product of nitrogen metabolism as urea rather than as
ammonia directly across the gills as occurs in most fish. The level of activity in liver of the first enzyme in the urea cycle pathway, carbamoyl-phosphate synthetase III (CPSase III), is too low to account
for the observed high rates of urea excretion. We report here the
surprising finding that CPSase III and all other urea cycle enzyme
activities are present in muscle of this species at levels more than
sufficient to account for the rate of urea excretion; in addition, the
basic kinetic properties of the CPSase III appear to be different from
those of other known type III CPSases. The sequence of the CPSase III
cDNA is reported as well as the finding that glutamine synthetase
activity is present in liver but not in muscle. This unusual form of
adaptation may have occurred because of the apparent impossibility of
packaging the needed amount of urea cycle enzymes in liver.
Muscle as the Primary Site of Urea Cycle Enzyme Activity in an
Alkaline Lake-adapted Tilapia, Oreochromis alcalicus
grahami
,,
,,
Department of Biochemistry and Molecular
Biology, University of Minnesota-Duluth, Duluth, Minnesota 55812, the § Rosenstiel School of Marine and Atmospheric Science,
University of Miami, Miami, Florida 33149-1098, the
¶ Department of Biology, McMaster University, Hamilton, Ontario
L8S4K1, Canada, and the Department of Zoology and Physiology,
University of Wyoming, Laramie, Wyoming 82071
Copyright © 1999 by The American Society for Biochemistry and Molecular Biology, Inc.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  D. Weihrauch, M. P. Wilkie, and P. J. Walsh Ammonia and urea transporters in gills of fish and aquatic crustaceans J. Exp. Biol., June 1, 2009; 212(11): 1716 - 1730. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Steele, P. H. Yancey, and P. A. Wright Dogmas and controversies in the handling of nitrogenous wastes: Osmoregulation during early embryonic development in the marine little skate Raja erinacea; response to changes in external salinity J. Exp. Biol., May 15, 2004; 207(12): 2021 - 2031. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. J. Walsh, G. D. Mayer, M. Medina, M. L. Bernstein, J. F. Barimo, and T. P. Mommsen A second glutamine synthetase gene with expression in the gills of the gulf toadfish (Opsanus beta) J. Exp. Biol., May 1, 2003; 206(9): 1523 - 1533. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Hirata, T. Kaneko, T. Ono, T. Nakazato, N. Furukawa, S. Hasegawa, S. Wakabayashi, M. Shigekawa, M.-H. Chang, M. F. Romero, et al. Mechanism of acid adaptation of a fish living in a pH 3.5 lake Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2003; 284(5): R1199 - R1212. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Steele, T. D. Chadwick, and P. A. Wright Ammonia detoxification and localization of urea cycle enzyme activity in embryos of the rainbow trout (Oncorhynchus mykiss) in relation to early tolerance to high environmental ammonia levels J. Exp. Biol., March 8, 2002; 204(12): 2145 - 2154. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. F. Terjesen, T. D. Chadwick, J. A. J. Verreth, I. Ronnestad, and P. A. Wright Pathways for urea production during early life of an air-breathing teleost, the African catfish Clarias gariepinus Burchell J. Exp. Biol., March 8, 2002; 204(12): 2155 - 2165. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K Iwata, M Kajimura, and T Sakamoto Functional ureogenesis in the gobiid fish Mugilogobius abei J. Exp. Biol., January 12, 2000; 203(24): 3703 - 3715. [Abstract] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |