title: Differential regulation of mRNA levels of acyl carrier protein isoforms in Arabidopsis.
abstract: All higher plants express several different acyl carrier protein (ACP) isoforms in a tissue-specific manner. We provide evidence that expression of mRNA for the most abundant ACP isoform in Arabidopsis leaves (ACP4) is increased severalfold by light, whereas mRNA levels for ACP isoforms 2 and 3 are independent of light. The presence of GATA-like motifs in the upstream region of the Acl1.4 gene (encoding for ACP4) and the similarity in light-mediated induction to ferredoxin-A mRNA suggests a direct role of light in Acl1.4 gene activation. Polyribosomal analysis indicated that light also affects the association of ACP transcripts with polysomes, similarly to mRNAs encoding ferredoxin-A. ACP2, ACP3, and ACP4 mRNA levels were also examined in Arabidopsis cell suspension culture and were found to be differentially controlled by metabolic and/or growth derived signals. Comparison of 5'-untranslated regions (UTRs) of ACP mRNAs of diverse plant species revealed two motifs that have been conserved during evolution, a CTCCGCC box and C-T-rich sequences. Fusions of the 5'-UTR sequences of ACP1 and ACP2 to luciferase and expression in transgenic plants indicated that the ACP1 leader contributes to preferential expression in seeds, whereas the ACP2 5'-UTR favored expression in roots. The deletion of 58 bp containing the conserved motifs of the ACP1 5'-UTR resulted in 10- to 20-fold lower gene expression in leaf and seed tissues of transgenic Arabidopsis plants.
authors.affiliation: Genetics Program, Michigan State University, East Lansing, Michigan 48824, USA.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Bonaventure
authors.forename: John B
authors.initials: JB
authors.lastname: Ohlrogge
mesh_terms: D000213:Acyl Carrier Protein / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000528:radiation effects; D008027:Light; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D030821:Plants, Genetically Modified; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D015533:Transcriptional Activation
chemical_list: D000213:Acyl Carrier Protein; D029681:Arabidopsis Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger