| Autor: |
Somanchi, Aravind, Barnes, Dwight, Mayfield, Stephen P. |
| Předmět: |
|
| Zdroj: |
Plant Journal; May2005, Vol. 42 Issue 3, p341-352, 12p |
| Abstrakt: |
Biosynthesis of chloroplast proteins is to a large extent regulated post-transcriptionally, and a number of nuclear-encoded genes have been identified that are required for translation or stability of specific chloroplast mRNAs. A nuclear mutant ofChlamydomonas reinhardtii, hf261, deficient in the translation of thepsbAmRNA, has reduced association of thepsbAmRNA with ribosomes and is deficient in binding of the chloroplast localized poly (A) binding protein (cPAB1) to thepsbAmRNA. Cloning of the hf261 locus and complementation of hf261 using a wt genomic clone has identified a novel gene,Tba1, for translational affector ofps. Strains complemented with the wtTba1gene restore the ability of thepsbA mRNA to associate with ribosomes, and restores RNA binding activity of cPAB1 for thepsbAmRNA. Analysis of theTba1gene identified a protein with significant homology to oxidoreductases. The effect ofTba1expression on the RNA binding activity of cPAB1, and on the association ofpsbAmRNA with ribosomes, implies that Tba1 functions as a redox regulator of cPAB1 RNA binding activity to indirectly promotepsbAmRNA translation initiation. A model of chloroplast translation incorporating Tba1 and other members of thepsbAmRNA binding complex is presented. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
Plný text