Intellectual Merit. Some microorganisms, notably cyanobacteria, are known to synthesize secondary metabolites that serve a sunscreen function to protect them from damaging effects of exposure to ultraviolet radiation (UV). In cyanobacteria, two main types of such compounds have been described: scytonemin, a unique alkaloid of interesting biological properties, and mycosporine-like amino acids (MAAs), a family of small water-soluble compounds derived from amino acids. In the past few years we have successfully developed the cyanobacterial strain, Nostoc punctiforme ATCC 29133, to study the genetic and molecular basis of such sunscreens. Great strides have been made during the past few years in this field of research. In this project we will be probing aspects of sunscreen biology that relate to the association of gene function with cell compartmentalization, to their regulation and their evolution. This work will provide links between existing knowledge at the molecular, physiological and environmental levels of organization, eventually enabling an integrated understanding of microbial sunscreens and setting the basis for their potential application.
Broader Impacts. Sunscreens are important factors in the ecological physiology of adaptation of many organisms in Nature, from plankton to corals at a time when increased UV-fluxes are of concern. Microbial sunscreens have attracted interest not only because they represent novel classes of secondary metabolites, but also because of their potential applicability for biotechnological purposes. Additionally, this research will represent a very attractive opportunity to populate ongoing efforts in outreach to STEM underrepresented minority K-12 students and the general public in Arizona, where protection from UV exposure is a constant concern, and where, we think, microbial sunscreens may offer an enticement to get to know the world of science.