N-myristoylation regulates the SnRK1 pathway in Arabidopsis.
Cotranslational and posttranslational modifications are increasingly recognized as important in the regulation of numerous essential cellular functions. N-myristoylation is a lipid modification ensuring the proper function and intracellular trafficking of proteins involved in many signaling pathways. Arabidopsis thaliana, like human, has two tightly regulated N-myristoyltransferase (NMT) genes, NMT1 and NMT2. Characterization of knockout mutants showed that NMT1 was strictly required for plant viability, whereas NMT2 accelerated flowering. NMT1 impairment induced extremely severe defects in the shoot apical meristem during embryonic development, causing growth arrest after germination. A transgenic plant line with an inducible NMT1 gene demonstrated that NMT1 expression had further effects at later stages. NMT2 did not compensate for NMT1 in the nmt1-1 mutant, but NMT2 overexpression resulted in shoot and root meristem abnormalities. Various data from complementation experiments in the nmt1-1 background, using either yeast or human NMTs, demonstrated a functional link between the developmental arrest of nmt1-1 mutants and the myristoylation state of an extremely small set of protein targets. We show here that protein N-myristoylation is systematically associated with shoot meristem development and that SnRK1 (for SNF1-related kinase) is one of its essential primary targets.
Pierre
Michèle
M
Protein Maturation and Cell Fate, Institut des Sciences du Végétal, Unité Propre de Recherche 2355, Centre National de la Recherche Scientifique, F-91198, Gif-sur-Yvette Cedex, France.
Traverso
José A
JA
Boisson
Bertrand
B
Domenichini
Séverine
S
Bouchez
David
D
Giglione
Carmela
C
Meinnel
Thierry
T
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology; D035264:Flowers / Q000187:drug effects / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D006801:Humans; D018519:Meristem / Q000166:cytology / Q000187:drug effects; D009024:Morphogenesis / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D019814:Myristic Acid / Q000378:metabolism*; D016366:Open Reading Frames; D010641:Phenotype; D018520:Plant Shoots / Q000166:cytology / Q000187:drug effects; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology; D012639:Seeds / Q000166:cytology / Q000187:drug effects; D013997:Time Factors