PMID- 18223148
OWN - NLM
STAT- MEDLINE
DCOM- 20080805
LR  - 20211020
IS  - 0032-0889 (Print)
IS  - 1532-2548 (Electronic)
IS  - 0032-0889 (Linking)
VI  - 146
IP  - 4
DP  - 2008 Apr
TI  - Arabidopsis NAD-malic enzyme functions as a homodimer and heterodimer and has a 
      major impact on nocturnal metabolism.
PG  - 1540-52
LID - 10.1104/pp.107.114975 [doi]
AB  - Although the nonphotosynthetic NAD-malic enzyme (NAD-ME) was assumed to play a 
      central role in the metabolite flux through the tricarboxylic acid cycle, the 
      knowledge on this enzyme is still limited. Here, we report on the identification 
      and characterization of two genes encoding mitochondrial NAD-MEs from Arabidopsis 
      (Arabidopsis thaliana), AtNAD-ME1 and AtNAD-ME2. The encoded proteins can be 
      grouped into the two clades found in the plant NAD-ME phylogenetic tree. 
      AtNAD-ME1 belongs to the clade that includes known alpha-subunits with molecular 
      masses of approximately 65 kD, while AtNAD-ME2 clusters with the known 
      beta-subunits with molecular masses of approximately 58 kD. The separated 
      recombinant proteins showed NAD-ME activity, presented comparable kinetic 
      properties, and are dimers in their active conformation. Native electrophoresis 
      coupled to denaturing electrophoresis revealed that in vivo AtNAD-ME forms a 
      dimer of nonidentical subunits in Arabidopsis. Further support for this 
      conclusion was obtained by reconstitution of the active heterodimer in vitro. The 
      characterization of loss-of-function mutants for both AtNAD-MEs indicated that 
      both proteins also exhibit enzymatic activity in vivo. Neither the single nor the 
      double mutants showed a growth or developmental phenotype, suggesting that NAD-ME 
      activity is not essential for normal autotrophic development. Nevertheless, 
      metabolic profiling of plants completely lacking NAD-ME activity revealed 
      differential patterns of modifications in light and dark periods and indicates a 
      major role for NAD-MEs during nocturnal metabolism.
FAU - Tronconi, Marcos A
AU  - Tronconi MA
AD  - Centro de Estudios Fotosinteticos y Bioquimicos, Universidad Nacional de Rosario, 
      2000 Rosario, Argentina.
FAU - Fahnenstich, Holger
AU  - Fahnenstich H
FAU - Gerrard Weehler, Mariel C
AU  - Gerrard Weehler MC
FAU - Andreo, Carlos S
AU  - Andreo CS
FAU - Flugge, Ulf-Ingo
AU  - Flugge UI
FAU - Drincovich, Maria F
AU  - Drincovich MF
FAU - Maurino, Veronica G
AU  - Maurino VG
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080125
PL  - United States
TA  - Plant Physiol
JT  - Plant physiology
JID - 0401224
RN  - 0 (Amino Acids)
RN  - 0 (DNA Primers)
RN  - 0 (Malates)
RN  - 0U46U6E8UK (NAD)
RN  - 817L1N4CKP (malic acid)
SB  - IM
MH  - Amino Acids/metabolism
MH  - Arabidopsis/*enzymology/genetics/metabolism
MH  - Base Sequence
MH  - Carbohydrate Metabolism
MH  - DNA Primers
MH  - *Darkness
MH  - Dimerization
MH  - Genes, Plant
MH  - Malates/chemistry/*metabolism
MH  - NAD/*metabolism
PMC - PMC2287332
EDAT- 2008/01/29 09:00
MHDA- 2008/08/06 09:00
PMCR- 2009/04/01
CRDT- 2008/01/29 09:00
PHST- 2008/01/29 09:00 [pubmed]
PHST- 2008/08/06 09:00 [medline]
PHST- 2008/01/29 09:00 [entrez]
PHST- 2009/04/01 00:00 [pmc-release]
AID - pp.107.114975 [pii]
AID - 114975 [pii]
AID - 10.1104/pp.107.114975 [doi]
PST - ppublish
SO  - Plant Physiol. 2008 Apr;146(4):1540-52. doi: 10.1104/pp.107.114975. Epub 2008 Jan 
      25.