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The conserved ELK-homeodomain of KNOTTED-1 contains two regions that signal nuclear localization.
- Source :
-
Plant molecular biology [Plant Mol Biol] 1996 Jan; Vol. 30 (1), pp. 1-14. - Publication Year :
- 1996
-
Abstract
- Nuclear localization serves as a regulatory mechanism in the activity of several transcription factors. KNOTTED-1 (Kn1) is a homeodomain protein likely to regulate vegetative development in maize. At least twelve genes related to Kn1 are known in maize and six in Arabidopsis. Ectopic expression of the maize, rice and Arabidopsis Kn1-related genes have been shown to alter cell fate determination. In this paper, we study the nuclear localization capabilities of the Kn1 homeodomain and the proximal amino acid residues (the ELK region) which is highly conserved among Kn1-related homeodomain proteins. The ELK homeodomain (ELK-HD) of Kn1 was fused to the reporter gene uidA encoding the bacterial enzyme beta-glucuronidase (GUS) and transformed into tobacco and onion cells. Quantitation of GUS activity in nuclear and total protein extracts from transgenic tobacco revealed a highly localized GUS activity in the nucleus for the ELK-HD/GUS fusion protein, as compared to the basal level of GUS activity in the nucleus for the GUS only protein. The ELK-HD/GUS transformants showed no unusual characteristics, thus indicating that expression of the putative Kn1 DNA-binding domain fused to GUS may be insufficient to create a dominant negative phenotype. Histochemical analysis of the onion epidermal cells transfected by particle bombardment demonstrated that greater than 50 % of the transformed onion epidermal cells showed higher levels of GUS staining in the nucleus relative to the cytoplasm. Deletion analysis of the ELK-HD revealed that the Kn1 homeodomain comprising the three predicted alpha-helices and the conserved ELK domain can each function independently as nuclear localization signals.
- Subjects :
- Amino Acid Sequence
Base Sequence
Conserved Sequence
Histocytochemistry
Homeodomain Proteins genetics
Molecular Sequence Data
Nuclear Proteins genetics
Plant Proteins genetics
Plants, Genetically Modified
Plants, Toxic
Recombinant Fusion Proteins metabolism
Sequence Deletion
Sequence Homology, Amino Acid
Nicotiana genetics
Vegetables genetics
Zea mays genetics
Cell Compartmentation
Cell Nucleus metabolism
Homeodomain Proteins metabolism
Nuclear Proteins metabolism
Plant Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0167-4412
- Volume :
- 30
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Plant molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 8616227
- Full Text :
- https://doi.org/10.1007/BF00017799