Knockdown of limiting-CO
 2
 –induced gene
 HLA3
 decreases HCO
 3
 −
 transport and photosynthetic Ci affinity in
 Chlamydomonas reinhardtii

Duanmu, Deqiang; Miller, Amy R.; Horken, Kempton M.; Weeks, Donald P.; Spalding, Martin H.

doi:10.1073/pnas.0812885106

Cited by 105 publications

(103 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is also clear, however, that even though it is dispensable, LCIB contributes to viability in very low CO 2 (Duanmu et al, 2009a), although neither its level of contribution to nor its precise role in Ci uptake under these conditions has been established. Two putative Ci transporters have been demonstrated to contribute LCIBindependent Ci uptake in C. reinhardtii .…”

mentioning

confidence: 99%

“…Two putative Ci transporters have been demonstrated to contribute LCIBindependent Ci uptake in C. reinhardtii . Knockdown of HLA3, a gene encoding an ATP-binding cassette transporter protein, causes growth defects in LCIB mutants in very low CO 2 and decreased Ci accumulation especially at a high pH (Duanmu et al, 2009a). HLA3 is predicted to be localized on the plasma membrane, and therefore is very likely involved in HCO 3 2 transport at this location.…”

mentioning

confidence: 99%

“…Some areas of uncertainty regarding key features of the microalgal CCM remain to be addressed. First, Ci, including the charged species, bicarbonate (HCO 3 reach Rubisco, yet the roles, if any, of proposed and confirmed Ci transporters, including the plasma membrane proteins HLA3 and Limiting CO 2 Inducible1 (LCI1) and the chloroplast envelope proteins LCIA (NAR1.2), CCP1, and CCP2 (Im and Grossman, 2002;Miura et al, 2004;Pollock et al, 2004;Mariscal et al, 2006;Duanmu et al, 2009a;Ohnishi et al, 2010), in acclimation and Ci uptake under different limiting CO 2 conditions are not yet clearly defined. Second, previous physiological studies have demonstrated that active uptake of both CO 2 and HCO 3 2 occurs in C. reinhardtii (Moroney and Tolbert, 1985;Sültemeyer et al, 1989), but the molecular components and the underlying mechanism responsible for active CO 2 uptake are still largely unknown.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Acclimation to Very Low CO₂: Contribution of Limiting CO₂ Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii

2014

Self Cite

View full text Add to dashboard Cite

The limiting-CO 2 inducible CO 2 -concentrating mechanism (CCM) of microalgae represents an effective strategy to capture CO 2 when its availability is limited. At least two limiting-CO 2 acclimation states, termed low CO 2 and very low CO 2 , have been demonstrated in the model microalga Chlamydomonas reinhardtii, and many questions still remain unanswered regarding both the regulation of these acclimation states and the molecular mechanism underlying operation of the CCM in these two states. This study examines the role of two proteins, Limiting CO 2 Inducible A (LCIA; also named NAR1.2) and LCIB, in the CCM of C. reinhardtii. The identification of an LCIA-LCIB double mutant based on its inability to survive in very low CO 2 suggests that both LCIA and LCIB are critical for survival in very low CO 2 . The contrasting effects of individual mutations in LCIB and LCIA compared with the effects of LCIB-LCIA double mutations on growth and inorganic carbon-dependent photosynthetic O 2 evolution reveal distinct roles of LCIA and LCIB in the CCM. Although both LCIA and LCIB are essential for very low CO 2 acclimation, LCIB appears to function in a CO 2 uptake system, whereas LCIA appears to be associated with a HCO 3 2 transport system. The contrasting and complementary roles of LCIA and LCIB in acclimation to low CO 2 and very low CO 2 suggest a possible mechanism of differential regulation of the CCM based on the inhibition of HCO 3 2 transporters by moderate to high levels of CO 2 .The CO 2 concentration in Earth's atmosphere has declined significantly since the origin of photosynthesis, and the current atmospheric CO 2 level is a major limiting factor for optimal photosynthesis in many plant species. Rubisco, the central enzyme catalyzing CO 2 assimilation, has a low affinity for CO 2 and a slow catalytic turnover rate for the carboxylation reaction, possibly as an evolutionary relic, and also catalyzes the competing oxygenation reaction between O 2 and ribulose-1,5-bisphosphate that releases fixed CO 2 through photorespiration. As a result, several adaptive strategies have evolved to improve photosynthetic efficiency by raising the CO 2 concentration at the site of Rubisco to increase the carboxylation rates and to suppress the wasteful photorespiration pathway. Among them, the cyanobacterial/ microalgal CO 2 -concentrating mechanism (CCM) appears to be one of the most effective strategies for CO 2 enrichment. These CCMs deploy diverse, active inorganic

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Acclimation to Very Low CO₂: Contribution of Limiting CO₂ Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii

2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…Another report suggested the close participation of CO 2 in inorganic nitrogen assimilation (for review, see Fernández et al, 2009). LCIA, or NAR1.2, is involved in the bicarbonate transport system in chloroplasts (Duanmu et al, 2009) but is not regulated by nitrogen availability, and has been identified as a low-CO 2 -inducible gene by expressed sequence tag (EST) analysis . However, NAR1 genes generally involve members of the formate/nitrite transporter family (Rexach et al, 2000).…”

Section: Molecular Mechanisms For High-co 2 Responsesmentioning

confidence: 99%

“…Dissolved inorganic carbon and nitrogen species drawn in bold dominate. CA, carbonic anhydrases; CA2, CAH2 Rawat & Moroney, 1991;Tachiki et al, 1992); NiR, nitrite reductase; NR, nitrate reductase; PG, 2-phosphoglycolate; PGA, 3-phosphoglycerate; PSII, photosystem II; Rh, Rh1 (Soupene et al, 2002;Yoshihara et al, 2008); T, (putative) transporters; Ta, LCIA (Duanmu et al, 2009;Mariscal et al, 2006); Tb, HANT/HANiT system IV (Galván et al, 1996;Rexach et al, 1999). CCM models of WT/LC cells, inorganic nitrogen assimilation, and photorespiratory carbon oxidation in C. reinhardtii are modified from Yamano et al (2010), Fernández et al (2009, and Spalding (2009), respectively.…”

Section: Molecular Mechanisms For High-co 2 Responsesmentioning

confidence: 99%

High-CO2 Response Mechanisms in Microalgae

Baba¹,

Shiraiwa²

2012

Advances in Photosynthesis - Fundamental Aspects

View full text Add to dashboard Cite

Algal Carbon Dioxide Concentrating Mechanisms

Mukherjee

Moroney

2011

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

Photosynthetic microorganisms like cyanobacteria and many eukaryotic algae acclimate to a limited availability of carbon dioxide (CO 2 ) in their environment by inducing a process called the carbon dioxide concentrating mechanism. This process uses an active inorganic carbon (C i ; CO 2 and/or HCO 3 − ) uptake system that leads to the internal accumulation of C i to levels significantly higher than extracellular levels. Carbonic anhydrase activity converts much of the accumulated hydrogen carbonate to CO 2 , concentrating this substrate around Rubisco and thereby optimising photosynthetic efficiency even under low CO 2 conditions. The efficiency of the process is further improved by the sequestration of Rubisco into specialised structures like the cyanobacterial carboxysome or the pyrenoid in eukaryotic algae. The carbon dioxide concentrating mechanism enhances carbon dioxide fixation and growth in algae. With the increasing demands for sustainable energy sources, algae with efficient carbon dioxide concentrating mechanisms are attractive models for biotechnological and transgenic applications for biofuel and biomass production. Key Concepts: The carbon dioxide concentrating mechanism helps photosynthetic algae optimise photosynthesis under limiting CO 2 conditions. Rubisco uses both carbon dioxide and oxygen as substrates. Rubisco is localised in the carboxysome in cyanobacteria and the pyrenoid in the green alga, Chlamydomonas reinhardtii. The charged hydrogen carbonate needs transporters to enter the cell and cross organellar membranes. Carbonic anhydrase is an efficient enzyme that carries out the reversible interconversion of carbon dioxide and hydrogen carbonate and this reaction proceeds at a much faster rate than the uncatalysed reaction. At higher pH levels most of the inorganic carbon is in the form of hydrogen carbonate. Most algae with carbon dioxide concentrating mechanisms can take up both carbon dioxide and hydrogen carbonate. Carbon dioxide can diffuse out of the cell so algae trap carbon dioxide in the form of the charged hydrogen carbonate anion. Algae are used for large‐scale biomass production and are currently being explored as sources of bio‐fuel.

show abstract

Knockdown of limiting-CO ₂ –induced gene HLA3 decreases HCO ₃ ⁻ transport and photosynthetic Ci affinity in Chlamydomonas reinhardtii

Cited by 105 publications

References 32 publications

Acclimation to Very Low CO₂: Contribution of Limiting CO₂ Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii

Acclimation to Very Low CO₂: Contribution of Limiting CO₂ Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii

High-CO2 Response Mechanisms in Microalgae

Algal Carbon Dioxide Concentrating Mechanisms

Contact Info

Product

Resources

About

Knockdown of limiting-CO 2 –induced gene HLA3 decreases HCO 3 − transport and photosynthetic Ci affinity in Chlamydomonas reinhardtii

Cited by 105 publications

References 32 publications

Acclimation to Very Low CO2: Contribution of Limiting CO2 Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii

Acclimation to Very Low CO2: Contribution of Limiting CO2 Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii

High-CO2 Response Mechanisms in Microalgae

Algal Carbon Dioxide Concentrating Mechanisms

Contact Info

Product

Resources

About

Knockdown of limiting-CO ₂ –induced gene HLA3 decreases HCO ₃ ⁻ transport and photosynthetic Ci affinity in Chlamydomonas reinhardtii

Acclimation to Very Low CO₂: Contribution of Limiting CO₂ Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii

Acclimation to Very Low CO₂: Contribution of Limiting CO₂ Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii