On the request of GNOBB members, Dr. Hemayet Ullah, Associate Professor, Dept. of Biology, Howard University, Washington DC gives important information about their discovery leading to the development of the immensely useful compounds to make some crops withstand salt/drought stress in the following words.
“Thanks a lot to many well wishers who have personally and publicly acknowledged the development of these immensely useful compounds to make some crops withstand salt/drought stress. Many of you asked for the technical background of this development and to keep abreast the wider scientific community at large, I have written a few non-technical sentences detailing the background of this development. Any suggestion, comments on the approach will be highly appreciated.
The genetic knock out of RACK1A gene makes model plant Arabidopsis drought/salt resistant. By realizing the extremely conserved RACK1 sequences across the plant kingdom, we reasoned that chemical knock-out of RACK1A will be more useful as this will allow to use the chemicals like fertilizer in crop plants and this will also allow to circumvent the controversy with the GMO approach of making crops drought resistant. In this regard, we deduced the crystal structure of RACK1A and through lab research identified some key residues on RACK1A protein that is absolutely needed for its function (phosphorylation and sumoylation sites of RACK1A). Thereafter, we screened (in silico) almost several million small compounds in a library (at Georgetown University) to find compounds that will bind to a key tyrosine phosphorylation site of RACK1A protein- thereby inhibiting phosphorylation of the key residue rendering RACK1A ‘inactive’. Now we have several dozens of compounds that binds to that particular site of RACK1A recombinant protein. We are still in lots of testing and retesting stages.
Though we have confirmed (through the use of SPR technique) the binding of few of the compounds to the recombinant RACK1A protein, current efforts are underway to co-crystallize the ‘drug’ bound RACK1A protein. Our manuscript is forthcoming.
You can see a video of tomato plants treated with/without the compounds under salt stress on my website or on our IP site
Thanks for your interest.
Hemayet Ullah, Ph.D.