Circadian Synthesis of a Nuclear-Encoded Chloroplast Glyceraldehyde-3-Phosphate Dehydrogenase in the Dinoflagellate Gonyaulax polyedra Is Translationally Controlled

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• 作者：Thomas Fagan ; David Morse ; and J. Woodland Hastings
• 刊名：Biochemistry
• 出版年：1999
• 出版时间：June 15, 1999
• 年：1999
• 卷：38
• 期：24
• 页码：7689 - 7695
• 全文大小：171K
• 年卷期：v.38,no.24(June 15, 1999)
• ISSN：1520-4995

文摘

The circadian clock has previously been shown to restrict synthesis of several proteins in thedinoflagellate Gonyaulax polyedra to only a few hours each day. We have identified one of these proteinsas glyceraldehyde-3-phosphate dehydrogenase. Two nuclear genes encoding the enzyme have been cloned,one corresponding to a cytoplasmic isoform and the other to a plastid targeted protein. On the basis ofprotein microsequence data, we conclude that the synthesis of the plastid isoform is clock-regulated. Thisregulation is not related to mRNA levels, which remain constant throughout the cycle, suggesting atranslational control mechanism, in contrast to the transcriptional regulation of GAPDH that has beendemonstrated in Neurospora. Although the rhythm of synthesis has a high amplitude, the abundance andactivity rhythms are greatly attenuated, which is attributed to the long half-life of the protein.