| 1. |
- Brakebusch, Cord, et al.
(författare)
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Brevican-deficient mice display impaired hippocampal CA1 long-term potentiation but show no obvious deficits in learning and memory
- 2002
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Ingår i: Molecular and Cellular Biology. - 0270-7306. ; 22:21, s. 7417-7427
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Tidskriftsartikel (refereegranskat)abstract
- Brevican is a brain-specific proteoglycan which is found in specialized extracellular matrix structures called perineuronal nets. Brevican increases the invasiveness of glioma cells in vivo and has been suggested to play a role in central nervous system fiber tract development. To study the role of brevican in the development and function of the brain, we generated mice lacking a functional brevican gene. These mice are viable and fertile and have a normal life span. Brain anatomy was normal, although alterations in the expression of neurocan were detected. Perineuronal nets formed but appeared to be less prominent in mutant than in wild-type mice. Brevican-deficient mice showed significant deficits in the maintenance of hippocampal long-term potentiation (LTP). However, no obvious impairment of excitatory and inhibitory synaptic transmission was found, suggesting a complex cause for the LTP defect. Detailed behavioral analysis revealed no statistically significant deficits in learning and memory. These data indicate that brevican is not crucial for brain development but has restricted structural and functional roles.
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| 2. |
- Gorny, Xenia, et al.
(författare)
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AKAP79/150 interacts with the neuronal calcium-binding protein caldendrin
- 2012
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Ingår i: Journal of Neurochemistry. - : Wiley. - 0022-3042 .- 1471-4159. ; 122:4, s. 714-726
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Tidskriftsartikel (refereegranskat)abstract
- The A kinase-anchoring protein AKAP79/150 is a postsynaptic scaffold molecule and a key regulator of signaling events. At the postsynapse it coordinates phosphorylation and dephosphorylation of receptors via anchoring kinases and phosphatases near their substrates. Interactions between AKAP79 and two Ca2+ -binding proteins caldendrin and calmodulin have been investigated here. Calmodulin is a known interaction partner of AKAP79/150 that has been shown to regulate activity of the kinase PKC in a Ca2+-dependent manner. Pull-down experiments and surface plasmon resonance biosensor analyses have been used here to demonstrate that AKAP79 can also interact with caldendrin, a neuronal calcium-binding protein implicated in regulation of Ca2+ -influx and release. We demonstrate that calmodulin and caldendrin compete for a partially overlapping binding site on AKAP79 and that their binding is differentially dependent on calcium. Therefore, this competition is regulated by calcium levels. Moreover, both proteins have different binding characteristics suggesting that the two proteins might play complementary roles. The postsynaptic enrichment, the complex binding mechanism, and the competition with calmodulin, makes caldendrin an interesting novel player in the signaling toolkit of the AKAP interactome.
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