Mitochondrial HO release does not directly cause damage to chromosomal DNA.

Reactive Oxygen Species (ROS) derived from mitochondrial respiration are frequently cited as a major source of chromosomal DNA mutations that contribute to cancer development and aging. However, experimental evidence showing that ROS released by mitochondria can directly damage nuclear DNA is largely lacking. In this study, we investigated the effects of HO released by mitochondria or produced at the nucleosomes using a titratable chemogenetic approach.

Oxygen-consumption based quantification of chemogenetic HO production in live human cells.

Reactive Oxygen Species (ROS) in the form of HO can act both as physiological signaling molecules as well as damaging agents, depending on their concentration and localization. The downstream biological effects of HO were often studied making use of exogenously added HO, generally as a bolus and at supraphysiological levels. But this does not mimic the continuous, low levels of intracellular HO production by for instance mitochondrial respiration.

GLB-3: A resilient, cysteine-rich, membrane-tethered globin expressed in the reproductive and nervous system of Caenorhabditis elegans.

The popular genetic model organism Caenorhabditis elegans (C. elegans) encodes 34 globins, whereby the few that are well-characterized show divergent properties besides the typical oxygen carrier function. Here, we present a biophysical characterization and expression analysis of C.

Modulating organelle distribution using light-inducible heterodimerization in .

The relative positioning of organelles underlies fundamental cellular processes, including signaling, polarization, and cellular growth. Here, we describe the usage of a light-dependent heterodimerization system, LOVpep-ePDZ, to alter organelle positioning locally and reversibly in order to study the functional consequences of organelle positioning. The protocol gives details on how to accomplish expression of fusion proteins encoding this system, describes the imaging parameters to achieve subcellular activation in , and may be adapted for use in other model systems.

Redox signaling modulates Rho activity and tissue contractility in the spermatheca.

Actomyosin-based contractility in smooth muscle and nonmuscle cells is regulated by signaling through the small GTPase Rho and by calcium-activated pathways. We use the myoepithelial cells of the spermatheca to study the mechanisms of coordinated myosin activation in vivo. Here, we show that redox signaling modulates RHO-1/Rho activity in this contractile tissue.