It was published in Science, the world's best and most prestigious scientific journal Vilnius University Life Sciences Center (VU GMC) chief researcher dr. Article by Gintutas Tamulaitis research group "Ribosomal stalk-captured CARF-RelE ribonuclease inhibits translation following CRISPR signaling"
CRISPR-Cas systems are one way bacteria protect themselves from viruses. Several types of protective CRISPR-Cas systems are found in bacteria, which differ in Cas proteins and their functions. Currently, the most well-known Cas9 and Cas12 proteins, also known as DNA gene scissors, are widely used genome editing tools in the world.
Dr. The group of scientists led by G. Tamulaitis is studying CRISPR-Cas10 bacterial protection systems against viruses, which are characterized by several different activities. When a virus attacks a bacterium, CRISPR-Cas10 destroys not only the DNA of the virus, like Cas9 or Cas12, but also the RNA, the viral transcripts. in 2017 In an article published in the journal Science, this team showed that the CRISPR-Cas10 antiviral systems, after recognizing viral RNA that has entered the cell, synthesize unique signaling molecules - cyclic oligoadenylates - that activate various auxiliary CARF effector proteins that recognize the signal and ensure protection against viruses.
New Science the publication is dr. Continuation of the successful scientific research carried out by the group of G. Tamulaitis. In it, VU researchers characterized a new family of protein effectors - Cami1 - using bioinformatic analysis, biochemical and structural studies. The research team showed that when the virus attacks the bacterium, CRISPR-Cas10 signaling molecules activate Cami1, a ribosome-dependent ribonuclease. "Activated Cami1 destroys RNA mediators involved in protein synthesis, thereby inhibiting cell growth. This allows the bacterium to save resources and prevents the virus from producing the necessary proteins", Dr. G. Tamulaitis.
Using X-ray structural analysis and cryo-electron microscopy (cryo-EM), VU researchers determined the structures of individual Cami1 and the complex of Cami1 with the protein synthesis machinery, the ribosome. Structural studies revealed how Cami1 is able to recognize and cleave only RNA mediators involved in protein synthesis. These studies revealed that the entry of Cami1 into the protein synthesis center of the ribosome is facilitated by interaction with a specialized structure of the ribosome stem. "It is interesting that plant antiviral ribosome-inactivating proteins use the same mechanism of access to ribosomes. This discovery revealed a novel virus suppression mechanism in the CRISPR-Cas antiviral defense system and demonstrated a common antiviral strategy shared by eukaryotes and bacteria. The knowledge about our characterized Cami1 proteins can be applied in biotechnology and therapeutics, creating new molecular tools," says Dr. G. Tamulaitis.
1 was used to visualize the ribosome-Cami2020 complex. Open access 200kV cryo transmission electron microscope "Glacios" was purchased from VU GMC. Research results obtained using this device were published this year in Nature and now in Science journals.
The research published in the "Science" magazine was carried out by a team of VU GMC scientists: Dr. Irmantas Mogila, dr. Giedrė Tamulaitienė, master's student Konstanty Keda, dr. Albert Timinskas, Audronė Rukšėnaitė, dr. Giedrius Sasnauskas, prof. Česlov Venclov, prof. Virginijus Šišknys and dr. Gintautas Tamulaitis.
Science is one of the most cited international scientific journals, publishing the best peer-reviewed research covering all areas of science and technology. Science group journals are published by the American Association for the Advancement of Science (AAAS), the oldest and largest scientific organization in the world.
