Defective splicing of the first nad4 intron is associated with lack of several complex I subunits in the Nicotiana sylvestris NMS1 nuclear mutant.
In this work, we provide evidence for the existence of a nuclear factor involved in the splicing of a specific mitochondrial intron in higher plants. In the Nicotiana sylvestris nuclear NMS1 mutant, defective in both vegetative and reproductive development, the first intron of the nad4 transcript encoding the complex I NAD4 subunit is not removed, whatever the tissue analysed. Transcript patterns of other standard mitochondrial genes are not affected in NMS1. However, numerous polypeptides are missing in two-dimensional in organelle mitochondrial protein synthesis patterns and several nuclear and mitochondrial complex I subunits are present in trace amounts. This indicates that translational or post-translational steps in the synthesis of other mitochondrial proteins are affected. All of these defects co-segregated with the abnormal phenotype in the offspring of a NMS1 x wild-type cross, showing that they are controlled by the same nuclear gene (MS1) or tightly linked loci. Such a complex situation has been described in chloroplasts and mitochondria of fungi, but never in higher plant mitochondria.
Brangeon
J
J
Institut de Biotechnologie des Plantes, UMR 8618-CNRS, Bâtiment 630, Université Paris-Sud, 91405 Orsay Cedex, France.
Sabar
M
M
Gutierres
S
S
Combettes
B
B
Bove
J
J
Gendy
C
C
Chétrit
P
P
Des Francs-Small
C C
CC
Pla
M
M
Vedel
F
F
De Paepe
R
R
D017398:Alternative Splicing; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003433:Crosses, Genetic; D018506:Gene Expression Regulation, Plant; D007438:Introns; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D009245:NADH Dehydrogenase / Q000737:chemistry / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics*; D010947:Plants, Toxic; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D014158:Transcription, Genetic
C084747:MST1 protein, Nicotiana tabacum; D009004:Monosaccharide Transport Proteins; D009687:Nuclear Proteins; D010940:Plant Proteins; D009245:NADH Dehydrogenase