RT-qPCR demonstrates light-dependent AtRBCS1A and AtRBCS3B mRNA expressions in Arabidopsis thaliana leaves.

Reverse transcription quantitative polymerase chain reaction (RT-qPCR) is widely used in diagnosis and research to determine specific mRNA expressions in cells. As RT-qPCR applications increase, it's necessary to provide undergraduates hands-on experience of this modern technique. Here, we report a 3-week laboratory exercise using RT-qPCR to demonstrate the light-dependent expressions of AtRBCS1A and AtRBCS3B genes encoding two Arabidopsis thaliana small subunits of the ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco).

Crosstalk signaling between mitochondrial Ca2+ and ROS.

Mitochondria are central to energy metabolism as the source of much of the cell's ATP, as well as being a hub for cellular Ca2+ signaling. Mitochondrial Ca2+ is a positive effector of ATP synthesis, yet Ca2+ overload can lead to mitochondrial dysfunction and cell death. Moreover, Ca2+ uptake by mitochondria is involved in shaping cellular Ca2+ dynamics by regulating the concentrations of Ca2+ within microdomains between mitochondria and sarco/endoplasmic reticulum and plasma membrane Ca2+ transporters.

Heme concentration dependence and metalloporphyrin inhibition of the system I and II cytochrome c assembly pathways.

Studies have indicated that specific heme delivery to apocytochrome c is a critical feature of the cytochrome c biogenesis pathways called system I and II. To determine directly the heme requirements of each system, including whether other metal porphyrins can be incorporated into cytochromes c, we engineered Escherichia coli so that the natural system I (ccmABCDEFGH) was deleted and exogenous porphyrins were the sole source of porphyrins (Delta hemA). The engineered E.

ABC transporter-mediated release of a haem chaperone allows cytochrome c biogenesis.

Although organisms from all kingdoms have either the system I or II cytochrome c biogenesis pathway, it has remained a mystery as to why these two distinct pathways have developed. We have previously shown evidence that the system I pathway has a higher affinity for haem than system II for cytochrome c biogenesis. Here, we show the mechanism by which the system I pathway can utilize haem at low levels.

Recombinant cytochromes c biogenesis systems I and II and analysis of haem delivery pathways in Escherichia coli.

Genetic analysis has indicated that the system II pathway for c-type cytochrome biogenesis in Bordetella pertussis requires at least four biogenesis proteins (CcsB, CcsA, DsbD and CcsX). In this study, the eight genes (ccmA-H) associated with the system I pathway in Escherichia coli were deleted. Using B.

Mutations in cytochrome assembly and periplasmic redox pathways in Bordetella pertussis.

Transposon mutagenesis of Bordetella pertussis was used to discover mutations in the cytochrome c biogenesis pathway called system II. Using a tetramethyl-p-phenylenediamine cytochrome c oxidase screen, 27 oxidase-negative mutants were isolated and characterized. Nine mutants were still able to synthesize c-type cytochromes and possessed insertions in the genes for cytochrome c oxidase subunits (ctaC, -D, and -E), heme a biosynthesis (ctaB), assembly of cytochrome c oxidase (sco2), or ferrochelatase (hemZ).

Chemiluminescent-based methods to detect subpicomole levels of c-type cytochromes.

A variety of luminol-based substrates and either an autoradiographic film or a charge-coupled device (CCD) imaging system were used for chemiluminescence detection of c-type cytochromes. The Pierce Femto peroxidase substrate was at least 10 times more sensitive when using film than the highly cited 3,3('),5,5(')-tetramethylbenzidine (benzidine derivative) staining method and 50 times more sensitive when using a CCD imaging system. Film or CCD imaging result in highly sensitive and quantitative signals.