Type II NAD(P)H dehydrogenases are targeted to mitochondria and chloroplasts in Arabidopsis thaliana

ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Western Australia, Australia.
FEBS Letters (Impact Factor: 3.17). 10/2008; 582(20):3073-9. DOI: 10.1016/j.febslet.2008.07.061
Source: PubMed


We found that four type II NAD(P)H dehydrogenases (ND) in Arabidopsis are targeted to two locations in the cell; NDC1 was targeted to mitochondria and chloroplasts, while NDA1, NDA2 and NDB1 were targeted to mitochondria and peroxisomes. Targeting of NDC1 to chloroplasts as well as mitochondria was shown using in vitro and in vivo uptake assays and dual targeting of NDC1 to plastids relies on regions in the mature part of the protein. Accumulation of NDA type dehydrogenases to peroxisomes and mitochondria was confirmed using Western blot analysis on highly purified organelle fractions. Targeting of ND proteins to mitochondria and peroxisomes is achieved by two separate signals, a C-terminal signal for peroxisomes and an N-terminal signal for mitochondria.

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    • "ripening ( Nashilevitz et al . , 2010 ) , so it could play a significant bioenergetic role . However , type II NAD ( P ) H dehydrogenase may also participate in chromorespiration ( Renato et al . , 2014 ) . Type II dehydrogenases are monomeric enzymes without proton pumping activity which are targeted to mitochondria , plastids , and peroxisomes ( Carrie et al . , 2008 ) . The presence of these enzymes in chromoplasts has not been yet tested , and further studies are needed to clarify this issue . Besides , the PQ pool is also reduced by PDS , which transfers the electrons resulting from the desaturation steps of phytoene during carotenoid biosynthesis ( Norris et al . , 1995 ) ."
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    ABSTRACT: Chlororespiration is a respiratory process located in chloroplast thylakoids which consists in an electron transport chain from NAD(P)H to oxygen. This respiratory chain involves the NAD(P)H dehydrogenase complex, the plastoquinone pool and the plastid terminal oxidase (PTOX), and it probably acts as a safety valve to prevent the over-reduction of the photosynthetic machinery in stress conditions. The existence of a similar respiratory activity in non-photosynthetic plastids has been less studied. Recently, it has been reported that tomato fruit chromoplasts present an oxygen consumption activity linked to ATP synthesis. Etioplasts and amyloplasts contain several electron carriers and some subunits of the ATP synthase, so they could harbor a similar respiratory process. This review provides an update on the study about respiratory processes in chromoplasts, identifying the major gaps that need to be addressed in future research. It also reviews the proteomic data of etioplasts and amyloplasts, which suggest the presence of a respiratory electron transport chain in these plastids.
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    • "ontain only traces of phylloquinone and accumulate demethyl phylloquinone rules out that other type II NADPH dehydrogenases contribute significantly to phylloquinone biosynthesis . In Arabi dopsis , such an absence of functional redundancy is not wholly unexpected because out of seven type II NADPH dehydrogenases , only NDC1 is found in plastids ( Carrie et al . , 2008 ; Xu et al . , 2013 ) . A similar scenario applies to rice , where the NDC1 ortholog is the sole plastid - targeted type II NADPH dehydrogenase ( Xu et al . , 2013 ) . By contrast , green fluorescent protein fusion experiments showed that the moss Physcomitrella patens possesses three plastid - targeted type II NADPH dehydrogenases ( Xu"
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    • "These processes include DNA replication and repair, transcription, translation, and proteolysis. Many proteins have been found to be dual-targeted between other organelles in plants, including mitochondria, plastids and cytosol (Small et al., 1998), mitochondrion, plastid and endoplasmic reticulum (Lee et al., 2011), nucleus and cytosol (Inze et al., 2012), plastids and nucleus (Schwacke et al., 2007), mitochondria and nucleus (Krause and Krupinska, 2009), plastids and peroxisomes (Reumann et al., 2007; Sapir-Mir et al., 2008), mitochondria and peroxisomes (Carrie et al., 2008, 2009), plastid and cytosol (Kiessling et al., 2004; Thatcher et al., 2007), mitochondria and cytosol (Duchene et al., 2001), Golgi-like vesicles and cytosol (Rautengarten et al., 2011), plastids and endoplasmic reticulum (Levitan et al., 2005), and mitochondrion and endoplasmic reticulum (Lee et al., 2011). In addition, some proteins associate with the exterior of an organelle but do not penetrate the hydrophobic membrane and thus, whilst actually cytosolic, appear localized to a specific organelle (Rautengarten et al., 2011). "
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    Full-text · Article · Aug 2014 · Frontiers in Plant Science
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