0000000000343352
AUTHOR
Henk A. Spierenburg
MPP1 links the Usher protein network and the Crumbs protein complex in the retina.
Contains fulltext : 53571.pdf (Publisher’s version ) (Closed access) The highly ordered distribution of neurons is an essential feature of a functional mammalian retina. Disruptions in the apico-basal polarity complexes at the outer limiting membrane (OLM) of the retina are associated with retinal patterning defects in vertebrates. We have analyzed the binding repertoire of MPP5/Pals1, a key member of the apico-basal Crumbs polarity complex, that has functionally conserved counterparts in zebrafish (nagie oko) and Drosophila (Stardust). We show that MPP5 interacts with its MAGUK family member MPP1/p55 at the OLM. Mechanistically, this interaction involves heterodimerization of both MAGUK mo…
Anti-B-50 (GAP-43) antibodies decrease exocytosis of glutamate in permeated synaptosomes.
Abstract The involvement of the protein kinase C substrate, B-50 (GAP-43), in the release of glutamate from small clear-cored vesicles in streptolysin-O-permeated synaptosomes was studied by using anti-B-50 antibodies. Glutamate release was induced from endogenous as well as 3 H -labelled pools in a [Ca2+]-dependent manner. This Ca2+-induced release was partially ATP dependent and blocked by the light-chain fragment of tetanus toxin, demonstrating its vesicular nature. Comparison of the effects of anti-B-50 antibodies on glutamate and noradrenaline release from permeated synaptosomes revealed two major differences. Firstly, Ca2+-induced glutamate release was decreased only partially by anti…