title: HIGH CHLOROPHYLL FLUORESCENCE145 Binds to and Stabilizes the psaA 5' UTR via a Newly Defined Repeat Motif in Embryophyta.
abstract: The seedling-lethal Arabidopsis thaliana high chlorophyll fluorescence145 (hcf145) mutation leads to reduced stability of the plastid tricistronic psaA-psaB-rps14 mRNA and photosystem I (PSI) deficiency. Here, we genetically mapped the HCF145 gene, which encodes a plant-specific, chloroplast-localized, modular protein containing two homologous domains related to the polyketide cyclase family comprising 37 annotated Arabidopsis proteins of unknown function. Two further highly conserved and previously uncharacterized tandem repeat motifs at the C terminus, herein designated the transcript binding motif repeat (TMR) domains, confer sequence-specific RNA binding capability to HCF145. Homologous TMR motifs are often found as multiple repeats in quite diverse proteins of green and red algae and in the cyanobacterium Microcoleus sp PCC 7113 with unknown function. HCF145 represents the only TMR protein found in vascular plants. Detailed analysis of hcf145 mutants in Arabidopsis and Physcomitrella patens as well as in vivo and in vitro RNA binding assays indicate that HCF145 has been recruited in embryophyta for the stabilization of the psaA-psaB-rps14 mRNA via specific binding to its 5' untranslated region. The polyketide cyclase-related motifs support association of the TMRs to the psaA RNA, presumably pointing to a regulatory role in adjusting PSI levels according to the requirements of the plant cell.
authors: Biozentrum der LMU München, Department Biologie I, 82152 Planegg-Martinsried, Germany.
authors: Nikolay
authors: http://orcid.org/0000-0003-2740-5991
authors: N
authors: Manavski
authors: Biozentrum der LMU München, Department Biologie I, 82152 Planegg-Martinsried, Germany.
authors: Salar
authors: S
authors: Torabi
authors: Biozentrum der LMU München, Department Biologie I, 82152 Planegg-Martinsried, Germany.
authors: Lina
authors: L
authors: Lezhneva
authors: Biozentrum der LMU München, Department Biologie I, 82152 Planegg-Martinsried, Germany.
authors: Muhammad Asif
authors: MA
authors: Arif
authors: Biozentrum der LMU München, Department Biologie I, 82152 Planegg-Martinsried, Germany.
authors: Wolfgang
authors: W
authors: Frank
authors: Biozentrum der LMU München, Department Biologie I, 82152 Planegg-Martinsried, Germany meurer@bio.lmu.de.
authors: Jörg
authors: http://orcid.org/0000-0003-2973-9514
authors: J
authors: Meurer
mesh_terms: D020121:5' Untranslated Regions; D000483:Alleles; D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D044002:Bryophyta / Q000235:genetics; D002736:Chloroplasts / Q000378:metabolism; D019669:Embryophyta / Q000235:genetics*; D005816:Genetic Complementation Test; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045331:Photosystem I Protein Complex / Q000235:genetics; D030821:Plants, Genetically Modified; D014176:Protein Biosynthesis; D020449:Repetitive Sequences, Amino Acid; D012269:Ribosomal Proteins / Q000235:genetics
chemical_list: D020121:5' Untranslated Regions; D029681:Arabidopsis Proteins; C487786:HCF145 protein, Arabidopsis; D009687:Nuclear Proteins; D045331:Photosystem I Protein Complex; D012269:Ribosomal Proteins; C089909:photosystem I, psaB subunit; C039747:ribosomal protein S14