https://scholars.lib.ntu.edu.tw/handle/123456789/615821
標題: | Phosphorylation of cysteine string protein-α up-regulates the frequency of cholinergic waves via starburst amacrine cells | 作者: | Ching-Feng Chen Rita R. Wo Chien-Ting Huang Tzu-Lin Cheng Juu-Chin Lu CHIH-TIEN WANG |
關鍵字: | PKA-mediated phosphorylation; cholinergic waves; cysteine string protein; retinal ganglion cells; starburst amacrine cells | 公開日期: | 2022 | 出版社: | CAMBRIDGE UNIV PRESS | 卷: | 39 | 來源出版物: | Visual Neuroscience | 摘要: | During the first postnatal week in rodents, cholinergic retinal waves initiate in starburst amacrine cells (SACs), propagating to retinal ganglion cells (RGCs) and visual centers, essential for visual circuit refinement. By modulating exocytosis in SACs, dynamic changes in the protein kinase A (PKA) activity can regulate the spatiotemporal patterns of cholinergic waves. Previously, cysteine string protein-α (CSPα) is found to interact with the core exocytotic machinery by PKA-mediated phosphorylation at serine 10 (S10). However, whether PKA-mediated CSPα phosphorylation may regulate cholinergic waves via SACs remains unknown. Here, we examined how CSPα phosphorylation in SACs regulates cholinergic waves. First, we identified that CSPα1 is the major isoform in developing rat SACs and the inner plexiform layer during the first postnatal week. Using SAC-specific expression, we found that the CSPα1-PKA-phosphodeficient mutant (CSP-S10A) decreased wave frequency, but did not alter the wave spatial correlation compared to control, wild-type CSPα1 (CSP-WT), or two PKA-phosphomimetic mutants (CSP-S10D and CSP-S10E). These suggest that CSPα-S10 phosphodeficiency in SACs dampens the frequency of cholinergic waves. Moreover, the level of phospho-PKA substrates was significantly reduced in SACs overexpressing CSP-S10A compared to control or CSP-WT, suggesting that the dampened wave frequency is correlated with the decreased PKA activity. Further, compared to control or CSP-WT, CSP-S10A in SACs reduced the periodicity of wave-associated postsynaptic currents (PSCs) in neighboring RGCs, suggesting that these RGCs received the weakened synaptic inputs from SACs overexpressing CSP-S10A. Finally, CSP-S10A in SACs decreased the PSC amplitude and the slope to peak PSC compared to control or CSP-WT, suggesting that CSPα-S10 phosphodeficiency may dampen the speed of the SAC-RGC transmission. Thus, via PKA-mediated phosphorylation, CSPα in SACs may facilitate the SAC-RGC transmission, contributing to the robust frequency of cholinergic waves. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/615821 | ISSN: | 0952-5238 1469-8714 |
DOI: | 10.1017/S0952523822000013 |
顯示於: | 分子與細胞生物學研究所 |
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