Dataset Information

Thylakoid Localized Type 2 NAD(P)H Dehydrogenase NdbA Optimizes Light-Activated Heterotrophic Growth of Synechocystis sp. PCC 6803

ABSTRACT: NdbA, one of the three type 2 NAD(P)H dehydrogenases (NDH-2) in Synechocystis sp. PCC 6803 (hereafter Synechocystis) was here localized to the thylakoid membrane, unique for the three NDH-2s, and investigated with respect to photosynthetic and cellular redox metabolism. For this purpose, a deletion mutant (ΔndbA) and a complementation strain overexpressing NdbA (ΔndbA::ndbA) were constructed. It is demonstrated that NdbA is expressed at very low level in the wild type (WT) Synechocystis under photoautotrophic (PA) growth whilst substantially higher expression occurs under light activated heterotrophic growth (LAHG). The absence of NdbA resulted in non-optimal growth of Synechocystis under LAHG and concomitantly enhanced the expression of photoprotection-related flavodiiron proteins and carbon acquisition-related proteins as well as various transporters. NdbA overexpression, on the other hand, promoted photosynthetic pigmentation and functionality of photosystem I under LAHG conditions while distinct photoprotective and carbon concentrating proteins were downregulated. NdbA overexpression also exerted an effect on the expression of many signaling and gene regulation proteins. It is concluded that NdbA, which accumulates in WT thylakoid membrane particularly under LAHG conditions, has a function in redox sensing and regulation, and ultimately fine-tunes the gene expression in Synechocystis cells to meet the requirements for optimal growth under LAHG conditions.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Synechocystis Sp. Pcc 6803

TISSUE(S): Photosynthetic Cell, Cell Culture

SUBMITTER: Dorota Muth-Pawlak

LAB HEAD: Eva Mari-Aro

PROVIDER: PXD011671 | Pride | 2019-03-15

REPOSITORIES: Pride

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			Action	DRS
	171005_OEndbA_LAH_1.msf	Msf
	171005_OEndbA_LAH_1.mzML	Mzml
	171005_OEndbA_LAH_1.mzid.gz	Mzid
	171005_OEndbA_LAH_1.raw	Raw
	171005_OEndbA_LAH_2.msf	Msf

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Thylakoid Localized Type 2 NAD(P)H Dehydrogenase NdbA Optimizes Light-Activated Heterotrophic Growth of Synechocystis sp. PCC 6803.

Huokko Tuomas T Muth-Pawlak Dorota D Aro Eva-Mari EM

Plant & cell physiology 20190601 6

NdbA, one of the three type 2 NAD(P)H dehydrogenases (NDH-2) in Synechocystis sp. PCC 6803 (hereafter Synechocystis) was here localized to the thylakoid membrane (TM), unique for the three NDH-2s, and investigated with respect to photosynthetic and cellular redox metabolism. For this purpose, a deletion mutant (ΔndbA) and a complementation strain overexpressing NdbA (ΔndbA::ndbA) were constructed. It is demonstrated that NdbA is expressed at very low level in the wild-type (WT) Synechocystis und ...[more]

PMID: 30847494

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Project description:The trophic condition related proteomes of an oxygenic photosynthetic cyanobacterium Synechocystis sp. PCC 6803 (glucose tolerant strain) were analyzed to get further insights into the metabolic traits governing the early exponential growth under photoautotrophic, mixotrophic and heterotrophic conditions. The cells were grown under constant light autotrophically (AT) in low (air-level) CO2 (ATLC) and in high CO2 (ATHC), mixotrophically (MT) in low (air-level) CO2 in the presence of glucose (MTLC) and heterotrophically in low (air-level) CO2 in the presence of glucose and only 10 min exposure to light every 24 hours (Light-Activated Heterotrophic Growth; LAHGLC). The proteomes of ATHC, MTLC and LAHGLC differed substantially from that of ATLC, particularly by downregulation of the inducible carbon concentrating mechanisms (CCM) and photorespiration related enzymes. On the contrary, under carbon-rich conditions (ATHC, MTLC, LAHGLC) the cells accumulated respiratory NAD(P)H dehydrogenase I complexes in the thylakoid membrane. In glucose supplemented cultures (MTLC, LAHGLC) a distinct NDH-2 protein, NdbA, additionally accumulated in the thylakoid membrane whilst the plasma membrane localized NdbC and ARTO decreased in abundance. The light-harvesting proteins together with the photosystem I and II subunits were uniquely depleted under LAHGLC condition, accumulated under ATHC and in MTLC remained at the level of the reference ATLC condition. The accumulation of P-transporters was unique, revealing only minor differences between ATLC and ATHC but strong up-regulation in MTLC and down-regulation in LAHGLC. This likely implies that MTLC stores energy surplus in the highly energetic bonds of polyphosphate polymer that can be used under unfavorable growth conditions. It is concluded that the rigor of cell growth in MTLC condition results to a great extent from high intracellular inorganic carbon conditions created upon glucose breakdown and release of CO2, beside the direct utilization of glucose-derived carbon skeletons for growth. This combination provides the MTLC cultures with excellent conditions for growth that often exceeds that of the mere photoautotrophic growth at high CO2.

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