Membrane Phosphorylation and the Action of Antidiuretic Hormone1

2015 ◽  
pp. 236-246
Author(s):  
I. L. Schwartz ◽  
P. A. Ripoche ◽  
R. Kinne
Keyword(s):  
Membrane Phosphorylation

scholarly journals Structural insights into the aPKC regulatory switch mechanism of the human cell polarity protein lethal giant larvae 2

2019 ◽  
Vol 116 (22) ◽  
pp. 10804-10812 ◽  
Author(s):  
Lior Almagor ◽  
Ivan S. Ufimtsev ◽  
Aruna Ayer ◽  
Jingzhi Li ◽  
William I. Weis
Keyword(s):  
Cell Polarity ◽  
Apical Membrane ◽  
Kinase C ◽  
Lethal Giant Larvae ◽  
Direct Binding ◽  
Switch Mechanism ◽  
Membrane Phosphorylation ◽  
Metazoan Cell ◽  
Structural Insights

Metazoan cell polarity is controlled by a set of highly conserved proteins. Lethal giant larvae (Lgl) functions in apical-basal polarity through phosphorylation-dependent interactions with several other proteins as well as the plasma membrane. Phosphorylation of Lgl by atypical protein kinase C (aPKC), a component of the partitioning-defective (Par) complex in epithelial cells, excludes Lgl from the apical membrane, a crucial step in the establishment of epithelial cell polarity. We present the crystal structures of human Lgl2 in both its unphosphorylated and aPKC-phosphorylated states. Lgl2 adopts a double β-propeller structure that is unchanged by aPKC phosphorylation of an unstructured loop in its second β-propeller, ruling out models of phosphorylation-dependent conformational change. We demonstrate that phosphorylation controls the direct binding of purified Lgl2 to negative phospholipids in vitro. We also show that a coil–helix transition of this region that is promoted by phosphatidylinositol 4,5-bisphosphate (PIP2) is also phosphorylation-dependent, implying a highly effective phosphorylative switch for membrane association.

Role of neurotransmitter release and cyclic AMP-dependent membrane phosphorylation in low voltage myocardial automaticity

1981 ◽  
Vol 37 (7) ◽  
pp. 731-734 ◽  
Author(s):  
M. E. Saxon ◽  
V. G. Safronova ◽  
A. V. Lazarev ◽  
A. A. Freidin ◽  
Y. M. Kokoz
Keyword(s):  
Cyclic Amp ◽  
Neurotransmitter Release ◽  
Low Voltage ◽  
Membrane Phosphorylation

Suggestion of a role for calmodulin and phosphorylation in regulation of rabbit ileal electrolyte transport: effects of promethazine

1986 ◽  
Vol 251 (5) ◽  
pp. G710-G717
Author(s):  
M. E. Cohen ◽  
G. W. Sharp ◽  
M. Donowitz
Keyword(s):  
Protein Phosphorylation ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrolyte Transport ◽  
Dependent Manner ◽  
Low Concentrations ◽  
Microvillus Membrane ◽  
Membrane Phosphorylation

Suggestion of a role for protein phosphorylation in the regulation of intestinal active NaCl transport was found by studying the effects of low concentrations of promethazine on Ca2+-calmodulin (CaM)-dependent protein phosphorylation of ileal microvillus membranes and on active ileal electrolyte transport. Ca2+-CaM increased the phosphorylation of six microvillus peptides (Mr 137,000, 116,000, 77,000, 58,000, 53,000, and 50,000) in a concentration-dependent manner. Promethazine inhibited the Ca2+-CaM-induced increases in each of these phosphorylations. The effect of promethazine was concentration dependent, with concentrations of 5–12 microM (mean 8 microM) causing 50% inhibition. Promethazine also caused a concentration-dependent increase in net Cl absorption and decrease in the ileal short-circuit current, with 9 microM promethazine causing a change in short-circuit current 50% of maximum. The promethazine effect on microvillus membrane phosphorylation was specific, since neither cAMP- and cGMP-induced phosphorylation in the microvillus membrane nor the stimulation by Ca2+-CaM of myosin light chain kinase phosphorylation of myosin light chain were affected by promethazine. The similar, and unusual sensitivity to low concentrations of promethazine on ileal microvillus membrane phosphorylation increased by Ca2+-CaM and on ileal electrolyte transport is consistent with Ca2+-CaM-dependent microvillus membrane phosphorylation being involved in the regulation of active electrolyte transport in ileal absorptive cells.

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