scholarly journals Homologous cardiac calcium pump regulators phospholamban and sarcolipin adopt distinct oligomeric states in the membrane

Author(s):  
Andy Y. Liu ◽  
Rodrigo Aguayo-Ortiz ◽  
Guadalupe Guerrero-Serna ◽  
Nulang Wang ◽  
Muriel G. Blin ◽  
...  
Keyword(s):  
Author(s):  
Anthony Paparo ◽  
Judy A. Murphy ◽  
Robert Dean

In the mid-1950's, fingernail clams virtually disappeared from a 100-mile section of the IL River, a tributary of the Mississippi River, due to unknown causes. A survey of the bottom fauna of the IL River in 1979, revealed that the clams were still absent from the middle reach of the River, where they had been abundant prior to the die-off in the 1950's. Some factor(s) in the River currently prevent the clams from recolonizing areas where they were formerly abundant. Recently, clams exposed to fluoride developed abnormal grooves in the shell matrix. Fluorides are known to be protoplasmic poisons removing essential body calcium by precipitation. Since the shell consists primarily of Ca carbonate, this investigation examines the possible role of fluoride on shell formation and the poisoning of the Ca pump which can directly inhibit lateral ciliary activity on the gill.


1993 ◽  
Vol 268 (4) ◽  
pp. 2368-2372
Author(s):  
C. Jouneaux ◽  
Y. Audigier ◽  
P. Goldsmith ◽  
F. Pecker ◽  
S. Lotersztajn

1996 ◽  
Vol 271 (3) ◽  
pp. C736-C741 ◽  
Author(s):  
W. Xu ◽  
C. Gatto ◽  
M. A. Milanick

Exchange inhibitory peptide (XIP; RRLLFYKYVYKRYRAGKQRG) is the shortest peptide that inhibits the plasma membrane Ca pump at high Ca (A. Enyedi, T. Vorherr, P. James, D. J. McCormick, A. G. Filoteo, E. Carafoli, and J. T. Penniston, J. Biol. Chem. 264: 12313-12321, 1989). Sulfosuccinimidyl acetate (SNA)-modified XIP does not inhibit the Ca pump; SNA neutralizes the positive charge on Lys at positions 7, 11, and 17. Peptide 2CK-XIP (RRLLFYRYVYRCYCAGRQKG) inhibits the pump, but the iodoacetamido-modified peptide does not inhibit. Three peptide analogues, in which 7, 11, and 17 were Ala, Cys, or Lys, inhibited about as well as XIP. SNA modification of these analogues (each with 1 Lys) did not inhibit. SNA modification of 2CK-XIP results in a peptide that does not inhibit; thus position 19 is important. Our results suggest that it is critical that position 19 be positively charged, that positions 7, 11, and 17 are important contact points between XIP and the Ca pump (with at least one positively charged), and that, whereas it is not essential that residues 12 and 14 be positive, they cannot be negative.


1990 ◽  
Vol 123 (4) ◽  
pp. 438-444 ◽  
Author(s):  
Yusuke Tsukamoto ◽  
Teiichi Tamura ◽  
Michiyo Saitoh ◽  
Yumiko Takita ◽  
Toshiaki Nakano

Abstract. To examine the hormonal regulation of the ATP-dependent Ca2+ pump in the kidneys, the ATP-dependent Ca2+ uptake by the basolateral membrane vesicles in the renal cortex was measured using radioactive calcium (45Ca2+) in rats with vitamin D deficiency or rats undergoing thyroparathyroidectomy. The Vmax of the Ca2+ pump activity was increased not only by administering calcitriol, but also by normalizing the serum calcium level in vitamin D-deficient rats. PTH suppressed the Ca2+ pump activity in normocalcemic vitamin D-deficient rats. Thyroparathyroidectomy did not affect the Ca2+ pump activity in the kidneys of normal rats. It was concluded that the ATP-dependent Ca2+ pump activity was depressed by secondary hyperparathyroidism in vitamin D-deficient rats.


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