Substance P and its fragments affect Ca2+/calmodulin-dependent synaptosomal membrane protein phosphorylation from rat cerebral cortex.
1. We have used synaptosomal membranes to study the influence of substance P and its fragments and analogues of its C-terminal fragment on Ca2+/calmodulin-dependent synapsin I endogenous phosphorylation. 2. SP1-11, SP1-4, [Tyr8]SP6-11 and [pGlu6, Tyr8]SP6-11 at 10(-3) M greatly inhibited synapsin I phosphorylation. 3. SP6-11 at all investigated concentrations and SP1-11, SP1-4, [Tyr8]SP6-11, [pGlu6, Tyr8]SP6-11 at 10(-4) and 10(-5) M were ineffective. 4. The results indicate that SP1-11 and its N-terminal fragment and analogues of its C-terminal fragment act on the phosphorylation of specific synaptic protein (synapsin I) and therefore may influence the release of neurotransmitters, membrane conductance and potentiation or inhibition of other signalling systems.
Hrabec
Z
Z
II Department of Biochemistry, Institute of Physiology and Biochemistry, School of Medicine, Lódź, Poland.
Szkudlarek
J
J
Lachowicz
L
L
D000818:Animals; D001345:Autoradiography; D002118:Calcium / Q000502:physiology*; D002147:Calmodulin / Q000502:physiology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000494:pharmacology*; D016704:Synapsins / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D002147:Calmodulin; D008565:Membrane Proteins; D010761:Phosphorus Radioisotopes; D016704:Synapsins; D013373:Substance P; D002118:Calcium