| Reference | 1. J Biotechnol. 2009 Oct 26;144(2):120-6. doi: 10.1016/j.jbiotec.2009.09.005. Epub
2009 Sep 15.
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Enhancement of pyruvate productivity by inducible expression of a F(0)F(1)-ATPase
inhibitor INH1 in Torulopsis glabrata CCTCC M202019.
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Zhou J(1), Huang L, Liu L, Chen J.
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Author information: <br>
(1)State Key Laboratory of Food Science and Technology, Jiangnan University,
Wuxi, Jiangsu, China.
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The aim of this study is to establish a controllable intracellular ATP content
regulation system applied to the enhancement of pyruvate production in Torulopsis
glabrata. The INH1 gene, which encodes a F(0)F(1)-ATPase inhibitor from
Saccharomyces cerevisiae, was expressed under a copper ion inducible promoter in
the pyruvate producer Torulopsis glabrata CCTCC M202019. The resultant strain was
designated as T. glabrata INH1. The induction efficiency was measured by the
inducible expression of an enhanced green fluorescence protein. The copper
inducible INH1 gene could control the intracellular ATP content (24 h) in an
extensive range between 0.192 mmol/mg protein and 0.642 mmol/mg protein in a
flask culture. With T. glabrataINH1, induction with 30 microM of Cu(2+) at 12 h
in a 3 L fermentor improved pyruvate yield from glucose on biomass by 29% and its
yield by 20%, respectively.
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2. FEMS Yeast Res. 2007 Aug;7(5):665-74. Epub 2007 Feb 5.
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The F1-ATPase inhibitor Inh1 (IF1) affects suppression of mtDNA loss-lethality in
Kluyveromyces lactis.
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Clark-Walker GD(1).
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Author information: <br>
(1)Molecular Genetics and Evolution Group, Research School of Biological
Sciences, The Australian National University, Canberra, Australia.
[email protected]
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Loss of mtDNA by the petite-negative yeast Kluyveromyces lactis is lethal
(rho(o)-lethality). However, mutations in the alpha, beta and gamma subunits of
F(1)-ATPase can suppress lethality by increasing intramitochondrial hydrolysis of
ATP. Increased hydrolysis of ATP can also occur on inactivation of Inh1, the
natural inhibitor of F(1)-ATPase. However, not all strains of K. lactis show
suppression of rho(o)-lethality on inactivation of INH1. Genetic analysis
indicates that one or more alleles of modifying factors are required for
suppression. Papillae showing enhanced resistance to ethidium bromide (EB) in
INH1 disruptants have mutations in the alpha, beta and gamma subunits of
F(1)-ATPase. Increased growth of double mutants on EB has been investigated by
disruption of INH1 in previously characterized atp suppressor mutants.
Inactivation of Inh1, with one exception, results in better growth on EB and
increased F(1)-ATPase activity, indicating that suppression of rho(o)-lethality
is not due to atp mutations preventing Inh1 from interacting with the
F(1)-complex. By contrast, in suppressor mutants altered in Arg435 of the beta
subunit, disruption of INH1 did not change the kinetic properties of F(1)-ATPase
or alter growth on EB. Consequently, Arg435 appears to be required for
interaction of Inh1 with the beta subunit. In a previous study, a mex1-1 allele
was found to enhance mgi(atp) expression. In accord with results from double
mutants, it has been found that mex1-1 is a frameshift mutation in INH1 causing
inactivation of Inh1p.
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3. J Biol Chem. 2002 Oct 18;277(42):39289-95. Epub 2002 Aug 6.
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Formation of the yeast F1F0-ATP synthase dimeric complex does not require the
ATPase inhibitor protein, Inh1.
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Dienhart M(1), Pfeiffer K, Schagger H, Stuart RA.
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Author information: <br>
(1)Department of Biology, Marquette University, Milwaukee, Wisconsin 53233, USA.
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The yeast F1F0-ATP synthase forms dimeric complexes in the mitochondrial inner
membrane and in a manner that is supported by the F0-sector subunits, Su e and Su
g. Furthermore, it has recently been demonstrated that the binding of the
F1F0-ATPase natural inhibitor protein to purified bovine F1-sectors can promote
their dimerization in solution (Cabezon, E., Arechaga, I., Jonathan P., Butler,
G., and Walker J. E. (2000) J. Biol. Chem. 275, 28353-28355). It was unclear
until now whether the binding of the inhibitor protein to the F1 domains
contributes to the process of F1F0-ATP synthase dimerization in intact
mitochondria. Here we have directly addressed the involvement of the yeast
inhibitor protein, Inh1, and its known accessory proteins, Stf1 and Stf2, in the
formation of the yeast F1F0-ATP synthase dimer. Using mitochondria isolated from
null mutants deficient in Inh1, Stf1, and Stf2, we demonstrate that formation of
the F(1)F(0)-ATP synthase dimers is not adversely affected by the absence of
these proteins. Furthermore, we demonstrate that the F1F0-ATPase monomers present
in su e null mutant mitochondria can be as effectively inhibited by Inh1, as its
dimeric counterpart in wild-type mitochondria. We conclude that dimerization of
the F1F0-ATP synthase complexes involves a physical interaction of the
membrane-embedded F0 sectors from two monomeric complexes and in a manner that is
independent of inhibitory activity of the Inh1 and accessory proteins.
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