Phytochrome regulates GTP-binding protein activity in the envelope of pea nuclei

• Published in: The Plant journal : for cell and molecular biology Vol. 4; no. 2; pp. 399 - 402
• Main Authors: Clark, G. B., Memon, A. R., Thompson, G. A. Jr, Roux, S. J.
• Format: Journal Article
• Language: English
• Published: Headquarters Blackwell Science Ltd 1993
• Subjects: Cell Nucleus - metabolism; GTP-Binding Proteins - metabolism; GTP-Binding Proteins - physiology; Life Sciences (General); Light; Phosphorus Radioisotopes; Phytochrome - metabolism; Pisum sativum - cytology; Pisum sativum - metabolism; Signal Transduction - physiology; Nasa Discipline Plant Biology; Nasa Program Space Biology; Nasa Discipline Number 40-50; Non-Nasa Center; NASA Program Space Biology; NASA Discipline Number 40-50; NASA Discipline Plant Biology; Non-NASA Center
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313X.1993.04020399.x

Three GTP-binding proteins with apparent molecular masses of 27, 28 and 30 kDa have been detected in isolated nuclei of etiolated pea plumules. After LDS-PAGE and transfer to nitrocellulose these proteins bind [32P]GTP in the presence of excess ATP, suggesting that they are monomeric G proteins. When nuclei are disrupted, three proteins co-purify with the nuclear envelope fraction and are highly enriched in this fraction. The level of [32P]GTP-binding for all three protein bands is significantly increased when harvested pea plumules are irradiated by red light, and this effect is reversed by far-red light. The results indicate that GTP-binding activity associated with the nuclear envelope of plant cells is photoreversibly regulated by the pigment phytochrome.