Schwaerzel Martin, Jaeckel Andrea, Mueller Uli
Saarland University, Faculty 8.3 Life Science, Department of Zoology and Physiology, 66041 Saarbrucken, Germany.
J Neurosci. 2007 Jan 31;27(5):1229-33. doi: 10.1523/JNEUROSCI.4622-06.2007.
The ubiquitous cAMP-protein kinase A (PKA) signaling pathway exhibits complex temporal requirements during the time course of associative memory processing. This directly raises questions about the molecular mechanisms that provide signaling specificity to this pathway. Here, we use Drosophila olfactory conditioning to show that divergent cAMP signaling is mediated by functionally distinct pools of PKA. One particular pool is organized via the PKA regulatory type II subunit at the level of A-kinase anchoring proteins (AKAPs), a family of scaffolding proteins that provides focal points of spatiotemporal signal integration. This AKAP-bound pool of PKA is acting within neurons of the mushroom bodies to support a late phase of aversive memory. The requirement for AKAP-bound PKA signaling is limited to aversive memory, but dispensable during appetitive memory. This finding suggests the existence of additional mechanisms to support divergence within the cAMP-PKA signaling pathway during memory processing. Together, our results show that subcellular organization of signaling components plays a key role in memory processing.
普遍存在的环磷酸腺苷-蛋白激酶A(PKA)信号通路在联想记忆处理的时间进程中表现出复杂的时间需求。这直接引发了关于为该通路提供信号特异性的分子机制的问题。在这里,我们利用果蝇嗅觉条件反射来表明,不同的环磷酸腺苷信号是由功能不同的PKA池介导的。一个特定的池是通过PKA调节II型亚基在A激酶锚定蛋白(AKAPs)水平上组织起来的,AKAPs是一类支架蛋白,提供时空信号整合的焦点。这种与AKAP结合的PKA池在蘑菇体的神经元内起作用,以支持厌恶记忆的后期阶段。对与AKAP结合的PKA信号的需求仅限于厌恶记忆,但在食欲记忆期间是可有可无的。这一发现表明,在记忆处理过程中,存在其他机制来支持环磷酸腺苷-PKA信号通路内的信号分歧。总之,我们的结果表明,信号成分的亚细胞组织在记忆处理中起关键作用。