ISSN:
1617-4623
Keywords:
Maize
;
Phosphoenolpyruvate carboxylase
;
DNA-binding proteins
;
C4 photosynthesis
;
Tissue specificity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The expression of the phosphoenolpyruvate carboxylase (PEPC) gene involved in C4 photosynthesis is regulated in a highly organized manner. Nuclear factors interacting with DNA fragments from the 5′ flanking region (from positions −1012 to +88 relative to the transcription start site) of the maize gene were identified by gel shift assays. Among the three kinds of such nuclear proteins (MNF1, MNF2a and MNF2b) found in the extract from maize leaves, MNF2a and MNF2b, which were distinguishable by their chromatographic behavior, interacted with the same motif of the repeated sequence (RS2) in the region from −432 to −201. MNF1 interacted with the region from −905 to −818 in which two copies of another kind of repeated sequence (RS1) reside. All of these nuclear factors were found only in the extracts from green and etiolated leaves but not in those from stems and roots. The relative content of MNFl and MNF2b was almost equal in green and etiolated leaves, while that of MNF2a was significantly higher in etiolated leaves than green leaves. It is suggested that expression of the PEPC gene is controlled by the combined effects of these nuclear factors.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00262425
