Premium
C hlamydomonas NZF 1, a tandem‐repeated zinc finger factor involved in nitrate signalling by controlling the regulatory gene NIT 2
Author(s) -
HIGUERA JOSE JAVIER,
FERNANDEZ EMILIO,
GALVAN AURORA
Publication year - 2014
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12305
Subject(s) - biology , mutant , nitrate , zinc finger , nitrogen assimilation , promoter , regulation of gene expression , biochemistry , gene expression , wild type , gene , transcription factor , microbiology and biotechnology , ecology
The C hlamydomonas reinhardtii NIT 2 gene plays a central role in nitrate assimilation, thus, nit2 mutants are not able to sense or to use nitrate for growth. NIT 2 protein is an RWP‐RK ‐type transcriptional factor related to nodule inception ( N in, NLP ) proteins from plants. NIT 2 expression is down‐regulated in ammonium and up‐regulated under nitrogen deprivation. However, intracellular nitrate is required to activate NIT 2 for subsequent expression of NIA 1 and other nitrate assimilation genes. In this work, mutants defective in nitrate sensing have been studied. The identification of genomic regions affected allows proposing putative loci /genes for nitrate signalling in the alga. Among them, a C r NZF 1 ( N itrate Z inc F inger 1) that encodes a tandem zinc finger protein CCCH ‐type. In the nzf1 mutant, the expression of the regulatory gene NIT 2 is decreased and also that of nitrate assimilation genes. In this mutant, polyadenylated forms of NIT 2 with different lengths could be detected, whereas in the wild type there appeared preferentially the longest forms. Cr NZF 1 is proposed to regulate NIT 2 polyadenylation and thus nitrate signalling and nitrate‐dependent growth in the alga.