Phosphatidylinositol 4,5-bisphosphate induced flunitrazepam sensitive-GABAA receptor increase in synaptosomes from chick forebrain.
The flunitrazepam sensitive-GABA(A) receptor density was increased by cytochalasins C and D at 37 degrees C suggesting that microfilament depolymerization induces exposure to the radioligand of a GABA(A) receptor in synaptosomes (Pharm Biochem Behav 72 (2002) 497). Similarly, phosphatidylinositol-4,5-bisphosphate (1-5 microM), but not a mixture of phospholipids, induced an increase of GABA(A) receptors in synaptosomes. Furthermore, N-ethyl maleimide, an inactivator of the sensitive fusion protein, which interacts with GABA(A) receptor, abolished the receptor increase induced by phosphatidylinositol-4,5-bisphosphate. Together, the results suggest that phosphatidylinositol-4,5-bisphosphate, acts via microfilament depolymerization increasing the binding of the radioligand to receptors possibly by modulation of their interaction with proteins involved in trafficking and docking mechanisms.
Cid
Mariana Paula
MP
Cátedra de Química Biológica, Departamento de Química, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba. Av, Vélez Sarsfield 1611, Córdoba, Argentina. aarce@efn.uncor.edu
Salvatierra
Nancy Alicia
NA
Arce
Augusto
A
D000818:Animals; D002645:Chickens / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005445:Flunitrazepam / Q000494:pharmacology*; D018757:GABA Modulators / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000494:pharmacology*; D016548:Prosencephalon / Q000187:drug effects / Q000378:metabolism*; D011869:Radioligand Assay; D011963:Receptors, GABA-A / Q000187:drug effects*; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D004791:Enzyme Inhibitors; D018757:GABA Modulators; D019269:Phosphatidylinositol 4,5-Diphosphate; D011963:Receptors, GABA-A; D005445:Flunitrazepam; D005033:Ethylmaleimide