At Emory, Kathy Griendling’s group is well known for studying NADPH oxidases (also known as Nox), enzymes which generate reactive oxygen species. In 2009, they published a paper on a regulator of Nox enzymes called Poldip2. Griendling’s former postdoc, now assistant professor, Alejandra San Martin has taken up Poldip2.
Griendling first came to Nox enzymes from a cardiology/vascular biology perspective, but they have links to cancer. Nox enzymes are multifarious and it appears that Poldip2 is too. As its full name suggests, Poldip2 (polymerase delta interacting protein 2) was first identified as interacting with DNA replication enzymes. Poldip2 also appears in mitochondria, indirectly regulating the process of lipoylation — attachment of a fatty acid to proteins anchoring them in membranes. That’s where a recent PNAS paper from San Martin, Griendling and colleagues comes in. It identifies Poldip2 as playing a role in hypoxia and cancer cell metabolic adaptation.
Part of the PNAS paper focuses on Poldip2 in triple-negative breast cancer, more difficult to treat. In TNBC cells, Poldip2’s absence appears to be part of the warped cancer cell metabolism known as the Warburg effect. Lab Land has explored the Warburg effect with Winship’s Jing Chen.
This image submitted by Thalita Abrahao won second place at the Postdoctoral Research Symposium Thursday. Abrahao, a postdoc in Kathy Griendlingâ€™s lab, is studying vesicle trafficking in vascular smooth muscle cells.
Thalita Abrahao — Kathy Griendling lab
Griendlingâ€™s lab has been looking into how the enzyme Nox4 and its partner Poldip2 are involved in cell migration, and Abrahao was investigating if vascular smooth muscle cells that have less Poldip2 have changes in protein processing.
Here, green represents beta-tubulin, a protein making up fine-looking fibers (microtubules) extending through the cell. Purple represents Sec23, part of the process of vesicle trafficking and protein secretion. White indicates when beta-tubulin and Sec23 are both present. Orange marks DNA in the nucleus.
Matthew Woodruff — Bali Pulendran lab
Kenneth Myers — James Zheng lab
Joshua Strauss — Elizabeth Wright lab
JoAnna Anderson — Francisco Alvarez lab
Alexey Tamas — Charles Searles lab
Emory’s Office of Postdoctoral Education is holding a Best Image contest. The deadline to vote is this Thursday, April 30. You can look at these beautiful images (and guess exactly what they are, based on what lab they come from), but to VOTE, you need to go to the OPE site.
This is part of the run up to their Postdoctoral Research Symposium at the end of May.
(Hat tip to Ashley Freeman in Dept of Medicine!)
Derek Lowe, a respected science blogger and drug discovery expert who was blogging when this writer was still working in the laboratory, today has a roundup of a concept that anyone hanging around Emory might have clued into already.
Namely, antioxidants arenâ€™t all theyâ€™re cracked up to be. Judging from the messages Gafas Ray Ban outlet to shoppers in the supermarket vitamin aisle, everybody needs more antioxidants. But evidence is accumulating that in some situations, antioxidants can be harmful: negating the adaptive effects of exercise on muscle tissue or even encouraging tumor growth, Lowe writes.
At Emory, Dean Jones has been patiently explaining for years that cells are not simply big bags with free radicals, thiols and antioxidants sloshing around indiscriminately. Instead, cells and oxidation-sensitive components are highly compartmentalized. Take for example, this recent paper in Molecular & Cellular Proteomics from Jones and Young-mi Go. Two major antioxidant systems in cells, glutathione and thioredoxin, function distinctly and independently, they show.
In a related vein, Kathy Griendlingâ€™s and David Lambethâ€™s labs were at the center of the discovery that reactive oxygen species are not only poisons that overflow from mitochondria, but important signals involved in many aspects of cell biology.
Kathy Griendling, PhD (in green), surrounded by members of her lab
On June 15, 2010, vascular biologist Kathy Griendling delivered the 2010 Dean’s Distinguished Faculty lecture at Emory University School of Medicine.
Some of Griendling’s publications have been cited thousands of times by fellow scientists around the world, making her the lead member of a small group of researchers at Emory called theÂ “Millipub Club.”
With her five children and one grandson watching in the back row, Griendling explained how she and her colleagues, over the course of more than two decades at Emory, have gradually revealed the functions of a family of enzymes called NADPH oxidases in vascular smooth muscle cells. Read more
Posted on June 28, 2010
by Quinn Eastman
David Lambeth, MD, PhD, with one of his paintings
NADPH oxidases (Nox for short) are enzymes that help plants fight off pathogens, guide sexual development in fungi, are essential for egg laying in flies and even help humans to sense gravity.
But what first attracted the interest of Emory researchers was the role of Nox in vascular disease and cancer. Along with Emory cardiologist Kathy Griendling, pathologist David Lambeth pioneered the discovery of how important these reactive oxygen-generating enzymes really are.
Lambeth will be honored this month in San Francisco by the Society for Free Radical Biology and Medicine with their 2009 Discovery Award.Â A profile in Emory Report explores his musical and artistic pursuits as well as his science.
Posted on November 4, 2009
by Quinn Eastman