Volume 9 Supplement 1

Seventeenth Annual Computational Neuroscience Meeting: CNS*2008

Open Access

The self-sustained regulation of PKMζ activity during the maintenance of L-LTP

BMC Neuroscience20089(Suppl 1):P54

DOI: 10.1186/1471-2202-9-S1-P54

Published: 11 July 2008

What could be the mechanism of enduring synaptic efficacies despite the fast turnover of proteins at synapses? The de-novo synthesis of plasticity related proteins may partially provide the answer. However, the newly synthesized proteins must be activated before they are functional which requires a persistent signal of second messenger. In contrast, to conventional kinases the PKMζ is an autonomous and constitutively active kinase, which does not require a second messenger for its sustained activity. Previous experimental results have shown that inhibiting PKMζ activity can effectively reverse the established L-LTP (3–5 hr in slices and 22 hrs in vivo) [13]. Here, we explore a question of what could be the mechanism to regulate the PKMζ activity during the maintenance of L-LTP. We propose a self-sustained regulation of PKMζ activity through another autonomously active kinase PDK1. Here, our specific instantiation of an activity regulation loop is the PKMζ-PDK1 molecular pair. The PDK1 regulates the PKMζ activity and its stability through a phosphorylation cycle [4]. We show that the PKMζ-PDK1 loop acts as a bistable switch. Our results imply that L-LTP induction should produce an increase in the total amount of PKMζ at active synapses, and this increase in PKMζ is maintained through activity regulation in the enduring phase of L-LTP (Fig 1). Our results also show that blocking the PKMζ activity in a dose dependent manner can effectively abolish the increase in total amount of PKMζ, (Fig 2) which is in consistent with previous experimental findings [1, 2].
https://static-content.springer.com/image/art%3A10.1186%2F1471-2202-9-S1-P54/MediaObjects/12868_2008_Article_877_Fig1_HTML.jpg
Figure 1

Bistability characteristics of the PKMζ-PDK1 molecular pair.

https://static-content.springer.com/image/art%3A10.1186%2F1471-2202-9-S1-P54/MediaObjects/12868_2008_Article_877_Fig2_HTML.jpg
Figure 2

Blocking the PKMζ activity during maintenance of L-LTP.

Authors’ Affiliations

(1)
Department of Neurobiology and Anatomy, The University of Texas, Medical School at Houston

References

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Copyright

© Aslam and Shouval; licensee BioMed Central Ltd. 2008

This article is published under license to BioMed Central Ltd.

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