The transport of phosphate (Pi) between subcellular compartments is central to
metabolic regulation. Although some of the transporters involved in controlling the
intracellular distribution of Pi have been identified in plants, others are predicted from
genetic and biochemical studies. The Arabidopsis thaliana genome encodes a family of
six proteins that share similarity with SLC17/type I Pi transporters, a diverse group of
animal proteins involved in the transport of Pi, organic anions and chloride.
Heterologous expression in yeast, and gene expression and localization studies in plants
were used to characterize all six members of this Arabidopsis family, which we have
named PHT4. All of the PHT4 proteins mediate Pi transport in yeast with high
specificity. Bioinformatic analysis and localization of PHT4-GFP fusion proteins
indicate that five of the proteins are targeted to the plastid inner envelope membrane, and
the sixth resides in the Golgi apparatus. PHT4 genes are expressed in both roots and
leaves although two of the genes are expressed predominantly in leaves and one mostly
in roots. These expression patterns, together with Pi transport activities and subcellular locations, suggest roles for PHT4 proteins in the transport of Pi between the cytosol and
chloroplasts, heterotrophic plastids and the Golgi apparatus.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2662 |
| Date | 15 May 2009 |
| Creators | Guo, Biwei |
| Contributors | Versaw, Wayne |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
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