Abstract
Purified chloroplasts from spinach and pea leaves were subfractionated into envelope, thylakoid, and stroma fractions and were analyzed for calmodulin-binding proteins using a 125I-calmodulin gel overlay assay. Calmodulin binding was primarily associated with a major polypeptide (M(r) 33,000) in the envelope membrane fraction. In contrast, major calmodulin-binding proteins were not detected in the thylakoid or stroma fractions. Our results provide the first evidence of calmodulin-binding proteins in the chloroplast envelope, and raise the possibility that calmodulin may contribute to the regulation of chloroplast function through its interaction with calmodulin-binding proteins in the chloroplast envelope. In addition, our results combined with those of other investigators support the proposal that subcellular organelles may be a primary site of calmodulin action.
Original language | English (US) |
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Pages (from-to) | 1644-1647 |
Number of pages | 4 |
Journal | Journal of Cell Biology |
Volume | 97 |
Issue number | 5 I |
DOIs | |
State | Published - 1983 |
ASJC Scopus subject areas
- Cell Biology