Mitochondria-associated hexokinases play a role in the control of programmed cell death in Nicotiana benthamiana

Moonil Kim, Jeong Hwa Lim, Chang Sook Ahn, Kyoungsook Park, Gyung Tae Kim, Woo Taek Kim, Hyunsook Pai

Research output: Contribution to journalArticle

136 Citations (Scopus)

Abstract

Recent findings suggest a pivotal role for mitochondria-associated hexokinase in the regulation of apoptosis in animal cells. In this study, virus-induced gene silencing (VIGS) of a hexokinase-encoding Hxk1 caused necrotic lesions on leaves, abnormal leaf morphology, and retarded plant growth in Nicotiana benthamiana. Hxk1 was associated with the mitochondria, and this association required the N-terminal membrane anchor. VIGS of Hxk1 reduced the cellular glucose-phosphorylating activity to ∼31% of control levels without changing the fructose-phosphorylating activity and did not alter hexose phosphate content severely. The affected cells showed programmed cell death (PCD) morphological markers, including nuclear condensation and DNA fragmentation. Similar to animal cell apoptosis, cytochrome c was released into the cytosol and caspase-9- and caspase-3-like proteolytic activities were strongly induced. Furthermore, based on flow cytometry, Arabidopsis thaliana plants overexpressing Arabidopsis HXK1 and HXK2, both of which are predominantly associated with mitochondria, exhibited enhanced resistance to H 2 O 2 - and α-picolinic acid-induced PCD. Finally, the addition of recombinant Hxk1 to mitochondria-enriched fractions prevented H 2 O 2 /clotrimazole-induced cytochrome c release and loss of mitochondria! membrane potential. Together, these results show that hexokinase critically regulates the execution of PCD in plant cells, suggesting a link between glucose metabolism and apoptosis.

Original languageEnglish
Pages (from-to)2341-2355
Number of pages15
JournalPlant Cell
Volume18
Issue number9
DOIs
Publication statusPublished - 2006 Sep 1

Fingerprint

Hexokinase
hexokinase
Nicotiana benthamiana
Tobacco
Mitochondria
mitochondria
Cell Death
apoptosis
Gene Silencing
Apoptosis
Cytochromes c
Arabidopsis
cytochrome c
gene silencing
Viruses
Clotrimazole
picolinic acid
Glucose
Hexoses
clotrimazole

All Science Journal Classification (ASJC) codes

  • Plant Science
  • Cell Biology

Cite this

Kim, Moonil ; Lim, Jeong Hwa ; Ahn, Chang Sook ; Park, Kyoungsook ; Kim, Gyung Tae ; Kim, Woo Taek ; Pai, Hyunsook. / Mitochondria-associated hexokinases play a role in the control of programmed cell death in Nicotiana benthamiana. In: Plant Cell. 2006 ; Vol. 18, No. 9. pp. 2341-2355.
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Mitochondria-associated hexokinases play a role in the control of programmed cell death in Nicotiana benthamiana. / Kim, Moonil; Lim, Jeong Hwa; Ahn, Chang Sook; Park, Kyoungsook; Kim, Gyung Tae; Kim, Woo Taek; Pai, Hyunsook.

In: Plant Cell, Vol. 18, No. 9, 01.09.2006, p. 2341-2355.

Research output: Contribution to journalArticle

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