TY - JOUR
T1 - LETM proteins play a role in the accumulation of mitochondrially encoded proteins in Arabidopsis thaliana and AtLETM2 displays parent of origin effects
AU - Zhang, Botao
AU - Carrie, Chris
AU - Ivanova, Aneta
AU - Narsai, Reena
AU - Murcha, Monika W.
AU - Duncan, Owen
AU - Wang, Yan
AU - Law, Simon R.
AU - Albrecht, Verónica
AU - Pogson, Barry
AU - Giraud, Estelle
AU - Van Aken, Olivier
AU - Whelan, James
PY - 2012/12/7
Y1 - 2012/12/7
N2 - The Arabidopsis thaliana genome contains two genes with homology to the mitochondrial protein LETM1 (leucine zipper-EF-hand-containing transmembrane protein). Inactivation of both genes, Atletm1 and Atletm2, together is lethal. Plants that are hemizygous for AtLETM2 and homozygous for Atletm1 (letm1(-/-) LETM2(+/-)) displayed a mild retarded growth phenotype during early seedling growth. It was shown that accumulation of mitochondrial proteins was reduced in hemizygous (letm1(-/-) LETM2(+/-)) plants. Examination of respiratory chain proteins by Western blotting, blue native PAGE, and enzymatic activity assays revealed that the steady state level of ATP synthase was reduced in abundance, whereas the steady state levels of other respiratory chain proteins remained unchanged. The absence of a functional maternal AtLETM2 allele in an Atletm1 mutant background resulted in early seed abortion. Reciprocal crosses revealed that maternally, but not paternally, derived AtLETM2 was absolutely required for seed development. This requirement for a functional maternal allele of AtLETM2 was confirmed using direct sequencing of reciprocal crosses of Col-0 and Ler accessions. Furthermore, AtLETM2 promoter β-glucuronidase constructs displayed exclusive maternal expression patterns.
AB - The Arabidopsis thaliana genome contains two genes with homology to the mitochondrial protein LETM1 (leucine zipper-EF-hand-containing transmembrane protein). Inactivation of both genes, Atletm1 and Atletm2, together is lethal. Plants that are hemizygous for AtLETM2 and homozygous for Atletm1 (letm1(-/-) LETM2(+/-)) displayed a mild retarded growth phenotype during early seedling growth. It was shown that accumulation of mitochondrial proteins was reduced in hemizygous (letm1(-/-) LETM2(+/-)) plants. Examination of respiratory chain proteins by Western blotting, blue native PAGE, and enzymatic activity assays revealed that the steady state level of ATP synthase was reduced in abundance, whereas the steady state levels of other respiratory chain proteins remained unchanged. The absence of a functional maternal AtLETM2 allele in an Atletm1 mutant background resulted in early seed abortion. Reciprocal crosses revealed that maternally, but not paternally, derived AtLETM2 was absolutely required for seed development. This requirement for a functional maternal allele of AtLETM2 was confirmed using direct sequencing of reciprocal crosses of Col-0 and Ler accessions. Furthermore, AtLETM2 promoter β-glucuronidase constructs displayed exclusive maternal expression patterns.
UR - http://www.scopus.com/inward/record.url?scp=84871311489&partnerID=8YFLogxK
U2 - 10.1074/jbc.M112.383836
DO - 10.1074/jbc.M112.383836
M3 - Article
SN - 0021-9258
VL - 287
SP - 41757
EP - 41773
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 50
ER -