High light induced changes in organization, protein profile and function of photosynthetic machinery in Chlamydomonas reinhardtii

2015 ◽  
Vol 152 ◽  
pp. 367-376 ◽  
Author(s):  
Srilatha Nama ◽  
Sai Kiran Madireddi ◽  
Elsin Raju Devadasu ◽  
Rajagopal Subramanyam
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Protein Profile ◽  
High Light ◽  
Photosynthetic Machinery ◽  
And Function ◽  
Induced Changes

scholarly journals Complementary vasoactivity and matrix remodelling in arterial adaptations to altered flow and pressure

2008 ◽  
Vol 6 (32) ◽  
pp. 293-306 ◽  
Author(s):  
A Valentín ◽  
L Cardamone ◽  
S Baek ◽  
J.D Humphrey
Keyword(s):  
Smooth Muscle ◽  
Continuum Theory ◽  
Muscle Contractility ◽  
Smooth Muscle Contractility ◽  
Rates Of Change ◽  
Biomechanical Loading ◽  
Smooth Muscle Proliferation ◽  
And Function ◽  
Diverse Data ◽  
Induced Changes

Arteries exhibit a remarkable ability to adapt to sustained alterations in biomechanical loading, probably via mechanisms that are similarly involved in many arterial pathologies and responses to treatment. Of particular note, diverse data suggest that cell and matrix turnover within vasoaltered states enables arteries to adapt to sustained changes in blood flow and pressure. The goal herein is to show explicitly how altered smooth muscle contractility and matrix growth and remodelling work together to adapt the geometry, structure, stiffness and function of a representative basilar artery. Towards this end, we employ a continuum theory of constrained mixtures to model evolving changes in the wall, which depend on both wall shear stress-induced changes in vasoactive molecules (which alter smooth muscle proliferation and synthesis of matrix) and intramural stress-induced changes in growth factors (which alter cell and matrix turnover). Simulations show, for example, that such considerations help explain the different rates of experimentally observed adaptations to increased versus decreased flows as well as differences in rates of change in response to increased flows or pressures.

scholarly journals Photoinhibition and continuous growth of the wild-type and a high-light tolerant strain of Chlamydomonas reinhardtii

2019 ◽  
Vol 57 (2) ◽  
pp. 617-626 ◽  
Author(s):  
O. VIRTANEN ◽  
D. VALEV ◽  
O. KRUSE ◽  
L. WOBBE ◽  
E. TYYSTJARVI
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
High Light ◽  
Wild Type ◽  
Continuous Growth ◽  
Tolerant Strain

scholarly journals The role of LHCBM1 in non-photochemical quenching in Chlamydomonas reinhardtii

2022 ◽  
Author(s):  
Xin Liu ◽  
Wojciech J Nawrocki ◽  
Roberta Croce
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Protein Complexes ◽  
Ph Sensor ◽  
High Light ◽  
Photochemical Quenching ◽  
Knock Out ◽  
Photosynthetic Organisms ◽  
Pigment Protein Complexes ◽  
Non Photochemical Quenching

Non-photochemical quenching (NPQ) is the process that protects photosynthetic organisms from photodamage by dissipating the energy absorbed in excess as heat. In the model green alga Chlamydomonas reinhardtii, NPQ was abolished in the knock-out mutants of the pigment-protein complexes LHCSR3 and LHCBM1. However, while LHCSR3 was shown to be a pH sensor and switching to a quenched conformation at low pH, the role of LHCBM1 in NPQ has not been elucidated yet. In this work, we combine biochemical and physiological measurements to study short-term high light acclimation of npq5, the mutant lacking LHCBM1. We show that while in low light in the absence of this complex, the antenna size of PSII is smaller than in its presence, this effect is marginal in high light, implying that a reduction of the antenna is not responsible for the low NPQ. We also show that the mutant expresses LHCSR3 at the WT level in high light, indicating that the absence of this complex is also not the reason. Finally, NPQ remains low in the mutant even when the pH is artificially lowered to values that can switch LHCSR3 to the quenched conformation. It is concluded that both LHCSR3 and LHCBM1 need to be present for the induction of NPQ and that LHCBM1 is the interacting partner of LHCSR3. This interaction can either enhance the quenching capacity of LHCSR3 or connect this complex with the PSII supercomplex.

Thallium Induced Changes in Behavioral Patterns: Correlation With Altered Lipid Peroxidation and Lysosomal Enzyme Activity in Brain Regions of Male Rats

1985 ◽  
Vol 1 (1) ◽  
pp. 81-98 ◽  
Author(s):  
David R. Brown ◽  
Barbara G. Callahan ◽  
Mark A. Cleaves ◽  
Robert A. Schatz
Keyword(s):  
Lipid Peroxidation ◽  
Lysosomal Enzyme ◽  
Brain Regions ◽  
Male Rats ◽  
Patterns Of Behavior ◽  
Low Levels ◽  
Behavioral Sequelae ◽  
Human Poisoning ◽  
And Function ◽  
Induced Changes

The effects of exposures to low levels of heavy metals is a complex and serious problem. Thallium is a metal which produces behavioral sequelae in human poisoning and is potentially hazardous with low level exposures. A test battery is presented which utilizes biochemical and behavioral testing to assess the effects of low levels of thallium on central nervous system chemistry and function in rats. The doses of thallium used (4 and 8 mg/kg) produced no overt signs of behavioral toxicity but did produce dose-related increases in lipid peroxidation and activation of the lysosomal enzyme beta-galactosidase in selected brain regions. At these dose levels, thallium also selectively altered the patterns of behavior. The study suggests that the target regions of thallium in the brain include the cortex, the cerebellum and the brainstem. The dose-response relationships, found for certain pairs of behavioral acts, were correlated with biochemical changes in one or more brain regions.

Cord blood rescues stroke-induced changes in splenocyte phenotype and function

2006 ◽  
Vol 199 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Martina Vendrame ◽  
Carmelina Gemma ◽  
Keith R. Pennypacker ◽  
Paula C. Bickford ◽  
Cyndy Davis Sanberg ◽  
...  
Keyword(s):  
Cord Blood ◽  
And Function ◽  
Induced Changes

petD mRNA maturation in Chlamydomonas reinhardtii chloroplasts: role of 5' endonucleolytic processing

1994 ◽  
Vol 14 (9) ◽  
pp. 6180-6186
Author(s):  
W Sakamoto ◽  
N R Sturm ◽  
K L Kindle ◽  
D B Stern
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Fusion Gene ◽  
Deletion Mutants ◽  
Chloroplast Genes ◽  
Coding Region ◽  
Higher Plant ◽  
Glucuronidase Activity ◽  
Mrna Maturation ◽  
Processing Site ◽  
And Function

Complex processing of primary transcripts occurs during the expression of higher-plant chloroplast genes. In Chlamydomonas reinhardtii, most chloroplast genes appear to possess their own promoters, rather than being transcribed as part of multicistronic operons. By generating specific deletion mutants, we show that petD, which encodes subunit IV of the cytochrome b6/f complex, has an RNA processing site that is required for accumulation of monocistronic petD mRNA in petD promoter deletion mutants; in such mutants, transcription of petD originates from the upstream petA promoter. The 5' ends of transcripts initiated at the petD promoter are probably also generated by processing, since the 5' end of monocistronic petD mRNA is the same in wild-type strains as it is in the petD promoter mutants. The location and function of the processing site were further examined by inserting petD-uidA fusion genes into the chloroplast genome (uidA is an Escherichia coli gene that encodes beta-glucuronidase). When a promoterless petD-uidA fusion gene was inserted downstream of petA, a monocistronic uidA transcript accumulated, which was apparently initiated at the petA promoter and was processed at a site corresponding precisely to the petD mRNA 5' end. When a construct including only sequences downstream of +25 relative to the mature mRNA 5' end was inserted into the same site, a dicistronic petA-uidA transcript accumulated but no monocistronic uidA transcript could be detected, suggesting that a processing site lies at least partially within the region from -1 to +25. Beta-glucuronidase activity was not detected in transformants that accumulated only the dicistronic petA-uidA transcript, suggesting that the first 25 bp of the 5' untranslated region are required for translation initiation. One explanation for this translational defect is that Chlamydomonas chloroplasts cannot translate the second coding region of some dicistronic messages.

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