SARS-CoV2 infectivity is potentially modulated by host redox status.

The current coronavirus disease (COVID-19) outbreak caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV2) has emerged as a threat to global social and economic systems. Disparity in the infection of SARS-CoV2 among host population and species is an established fact without any clear explanation. To initiate infection, viral S-protein binds to the Angiotensin-Converting Enzyme 2 (ACE2) receptor of the host cell.

A heat-activated MAP kinase (HAMK) as a mediator of heat shock response in tobacco cells.

A heat-activated MAP kinase (HAMK), immunologically related to the extracellular signal-regulated kinase (ERK) super-family of protein kinases, has been identified in BY2 cells of tobacco. The activation of HAMK at 37 degrees C was transient and detected within 2 min and reached a maximum level within 5 min. Ca(2+) chelators and channel blockers, and the known inhibitors of MEK, a MAP kinase kinase, prevented the heat activation of HAMK.

In vivo and in vitro activation of temperature-responsive plant map kinases.

Alfalfa cells possess two temperature-responsive Mitogen-Activated Protein Kinases (MAPKs), SAMK (Stress-Activated MAP Kinase) activated at 4 degrees C and HAMK (Heat shock-Activated MAP Kinase) activated at 37 degrees C. Both are inactive at 25 degrees C. We show here that SAMK is activated when cells are transferred from 37 degrees C to 25 degrees C, and HAMK is activated when cells are transferred from 4 degrees C to 25 degrees C.

Opposite changes in membrane fluidity mimic cold and heat stress activation of distinct plant MAP kinase pathways.

Mitogen-activated protein kinases (MAPKs) appear to be ubiquitously involved in signal transduction during eukaryotic responses to extracellular stimuli. In plants, no heat shock-activated MAPK has so far been reported. Also, whereas cold activates specific plant MAPKs such as alfalfa SAMK, mechanisms of such activation are unknown.