LAUSR

New molecular communication in type III CRISPR-Cas systems has been identified The CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated protein) system is known to protect bacteria against foreign invading DNA, usually from phages (viruses that infect bacteria) or plasmids (circular DNA found in the cytoplasm of bacteria). Since the first demonstration of CRISPR-Cas functionality a decade ago (1), mechanistic understanding of CRISPR-Cas has not only enabled genome editing but also revolutionized our appreciation of bacterial defense against their viruses. CRISPR-Cas systems show a high degree of sophistication in providing immunity against phages, including elaborate mechanisms to accurately identify the invading DNA, safety checks to prevent self-targeting (2), and high diversity of target destruction mechanisms among different types of CRISPR-Cas systems (3). Kazlauskiene et al. (4), on page 605 of this issue, and a study by Niewoehner et al. (5) report the discovery of an unexpected aspect of CRISPR-Cas immunity: intracellular signaling.