Nitrite transport activity of a novel HPP family protein conserved in cyanobacteria and chloroplasts.

摘要: Some cyanobacterial genomes encode an integral membrane protein of the HPP family, which exhibited nitrite transport activity when expressed in transport-less NA4 mutant cyanobacterium Synechococcus elongatus strain PCC 7942. AT5G62720 and AT3G47980 were found to Arabidopsis homologs protein. The product was localized chloroplast envelope shown confer uptake on with N-terminally truncated transit peptide or as a fusion N-terminal region family Kinetic analyses showed that has much higher affinity for (K(m) = 13 µM) than 150 µM). Illuminated chloroplasts isolated from lines lower wild-type Col-0 plants, while mutants AT1G68570 (AtNPF3.1), gene previously reported plastid transporter AtNitr1, levels activity. roots but not shoots. It putative similar its low significant cell. Transcription (AtNITR2;1) (AtNITR2;2) stimulated by nitrate under control NIN-like proteins, suggesting proteins represent nitrate-inducible components system plastids.