Zaccolo M, Di Benedetto G, Lissandron V, Mancuso L, Terrin A, Zamparo I
Dulbecco Telethon Institute, Venetian Institute of Molecular Medicine, Via Orus 2, 35100 Padova, Italy.
Biochem Soc Trans. 2006 Aug;34(Pt 4):495-7. doi: 10.1042/BST0340495.
It is becoming increasingly evident that the freely diffusible second messenger cAMP can transduce specific responses by localized signalling. The machinery that underpins compartmentalized cAMP signalling is only now becoming appreciated. Adenylate cyclases, the enzymes that synthesize cAMP, are localized at discrete parts of the plasma membrane, and phosphodiesterases, the enzymes that degrade cAMP, can be targeted to selected subcellular compartments. A-kinase-anchoring proteins then serve to anchor PKA (protein kinase A) close to specific targets, resulting in selective activation. The specific activation of such individual subsets of PKA requires that cAMP is made available in discrete compartments. In this presentation, the molecular and structural mechanisms responsible for compartmentalized PKA signalling and restricted diffusion of cAMP will be discussed.
越来越明显的是，可自由扩散的第二信使环磷酸腺苷（cAMP）能够通过局部信号传导转导特定反应。支撑cAMP信号分隔的机制直到现在才开始得到认识。合成cAMP的酶——腺苷酸环化酶定位于质膜的离散部分，而降解cAMP的酶——磷酸二酯酶可以靶向特定的亚细胞区室。A激酶锚定蛋白随后将蛋白激酶A（PKA）锚定在特定靶点附近，从而导致选择性激活。PKA这些单独亚群的特异性激活要求cAMP在离散区室中可用。在本报告中，将讨论负责PKA信号分隔和cAMP受限扩散的分子和结构机制。
