new mitochondrial protein structure - form and function!

 

My brother who is a graphic designer in Chicago came across this and sent it to me over the weekend. You learned about the roles of mitochondrial protein complexes in cellular respiration from Dr. Goldstein - now get a whole new perspective on them!

WWhat I loved about this discovery is that it connects form and function. The way the many proteins of cellular respiration pathways physically fit together in the mitochondrial inner membrane causes the membrane to bend, helping to explain how convoluted the inner membrane is. This bending helps maximize the surface area of the inner membrane within the bounds of the smooth outer membrane. 

And I didn't know this, but apparently an earlier discovery was that the ATP synthase polymerizes into a helical fiber! 

cutting-edge research on focal adhesions

 

Rae Cho here at UNC is working on focal adhesions in muscle cells, and considering what they call a "radical form of post-translational modification." 

Remember proteolysis from the Signaling lesson about the Delta-Notch signaling cascade? Professor Cho is studying proteolysis in the context of cell-substrate adhesion. It's a compelling way to make a irreversible or slowly reversible change such as those needed for cell differentiation. 

Read more about our colleague here! They have a good sense of humor and celebrate the company of their furry friends.

Weaponizing matrix metalloproteinases

Remember how impermeable that basal lamina looked in today's lesson's electron micrograph of a torn epithelium? Cancer cells can actually break right through such barriers, to gain access to the circulatory system and begin a metastatic journey. 

How do they break through? Matrix metalloproteinases (MMPs) are proteins that when bound to a metal (such as zinc) can break down other proteins. They are typically secreted into the extracellular space.

MMPs weren't "invented" for cancer, though; they're important for development, when cells need to break from one compartment of the body to another in order to set up the body plan and build organs.

MMPs are seen in the genomes of organisms besides humans (and related mammals) - they're expressed by venomous snakes! It turns out snake venom is so destructive because it contains MMPs. Venoms can induce much of their harm by causing hemorrhage (breaking down blood vessels and inhibiting clotting).

There is a whole field of Venomics (get it? Like genomics, transcriptomics, proteomics, etc) in which folks are working to better understand the molecular and cellular biology and the biochemistry of venom proteins including MMPs in order to engineer them for therapies, develop anti-venom treatments, and widen our understanding of the diversity of protein function.