Activity-dependent regulation of neurohormone synthesis and its impact on reproductive behavior in aplysia.
Activity-dependent regulation of neurohormone synthesis and its impact on reproductive behavior in aplysia.
复制标题
神经激素合成的活动依赖性调节及其对海兔生殖行为的影响。
DOI：
10.1095/biolreprod.103.022491
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Sossin,WayneS
中科院分区：
文献类型：
--
作者：
Wayne,NancyL;Lee,Wenjau;Michel,Stephan;Dyer,John;Sossin,WayneS
The bag cell neurons (BCNs) of the molluskAplysia californicaprovide a simple model system for investigating cellular and molecular events regulating synthesis and secretion of a reproductive neuropeptide and their impact on physiology and behavior. The BCNs secrete a large amount of egg-laying hormone (ELH) in response to an electrical afterdischarge. The afterdischarge also triggers cellular and molecular events leading to upregulation of ELH biosynthesis to replenish the supply of releasable hormone that was lost because of secretion. In the present review, we discuss signal-transduction events that link membrane excitability to ELH biosynthesis. We present evidence that the afterdischarge stimulates ELH synthesis by upregulating translation of ELH mRNA rather than by activating ELH gene transcription. This increase in ELH synthesis is accompanied by a decrease in total protein synthesis, suggesting that the synthetic machinery is being funneled selectively toward ELH. We also discuss work showing that afterdischarge-induced ELH synthesis uses a novel mechanism of translation initiation, one involving a switch from cap-dependent to cap-independent translation initiation that activates an internal ribosome entry site (IRES) located in the 5′-untranslated region of ELH mRNA. The IRES-regulated translation provides a unique cellular mechanism to selectively upregulate synthesis of a critical reproductive hormone at the expense of nonessential proteins.
