Identification of genes transcriptionally regulated by the Ccm1 gene by using Chlamydomonas cDNA macroarray

• Published in: Journal of plant research Vol. 115; p. 182
• Main Authors: Miura, K, Kohinata, T, Yoshioka, S, Yamano, T, Shimada, E, Asamizu, E, Nakamura, Y, Tabata, S, Yamato, K T, Ohyama, K, Fukuzawa, H
• Format: Journal Article
• Language: English
• Published: 01.12.2002
• Subjects: Ccm1 gene; Chlamydomonas; DNA microarrays
• ISSN: 0918-9440

Acclimation to CO sub(2)-limiting stress is associated with induction of a set of genes for a carbon-concentrating mechanism (CCM) through signal transduction pathway. A regulatory gene, Ccm1, which plays a critical role in this pathway, have been identified. To identify genes transcriptionally regulated by Ccm1, expression profiles of Wt and the ccm1 mutant were examined simultaneously by Chlamydomonas cDNA macroarray (10,368 EST). Macroarray analyses enabled us to detect 53 low-CO sub(2) inducible (Lci) genes and 59 genes regulated by Ccm1, whose mRNA levels were changed by more than 2.5-fold. Of these, 48 Lci genes were regulated by Ccm1, indicating Ccm1 is a higher position in gene hierarchy of CO sub(2) signal transduction pathway. In 48 genes, 7 genes involved in photorespiration were also included, suggesting that the photorespiratory cycle is controlled by Ccm1 as well as CCM. Moreover, northern blot analyses and sequence analyses suggests that several Lci genes containing transmembrane domains would play a role in the inorganic carbon uptake. Of these genes, one gene has similarities with anion transporter and signal peptide for localization of chloroplast membrane. mRNA transcript level of 11 genes were not altered by change of CO sub(2) concentration, but were regulated by Ccm1. Cah3 coding for chloroplast carbonic anhydrase, which plays substantial role in CCM, was also included in these genes.