Luminidependens (LD) is an Arabidopsis protein with prion behavior.
Prion proteins provide a unique mode of biochemical memory through self-perpetuating changes in protein conformation and function. They have been studied in fungi and mammals, but not yet identified in plants. Using a computational model, we identified candidate prion domains (PrDs) in nearly 500 plant proteins. Plant flowering is of particular interest with respect to biological memory, because its regulation involves remembering and integrating previously experienced environmental conditions. We investigated the prion-forming capacity of three prion candidates involved in flowering using a yeast model, where prion attributes are well defined and readily tested. In yeast, prions heritably change protein functions by templating monomers into higher-order assemblies. For most yeast prions, the capacity to convert into a prion resides in a distinct prion domain. Thus, new prion-forming domains can be identified by functional complementation of a known prion domain. The prion-like domains (PrDs) of all three of the tested proteins formed higher-order oligomers. Uniquely, the Luminidependens PrD (LDPrD) fully replaced the prion-domain functions of a well-characterized yeast prion, Sup35. Our results suggest that prion-like conformational switches are evolutionarily conserved and might function in a wide variety of normal biological processes.
Whitehead Institute for Biomedical Research, Cambridge, MA 02142;
Sohini
S
Chakrabortee
Whitehead Institute for Biomedical Research, Cambridge, MA 02142;
Can
C
Kayatekin
Whitehead Institute for Biomedical Research, Cambridge, MA 02142; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139;
Greg A
GA
Newby
Whitehead Institute for Biomedical Research, Cambridge, MA 02142;
Marc L
ML
Mendillo
Whitehead Institute for Biomedical Research, Cambridge, MA 02142;
Alex
A
Lancaster
Whitehead Institute for Biomedical Research, Cambridge, MA 02142; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139; Howard Hughes Medical Institute, Cambridge, MA 02139 lindquist_admin@wi.mit.edu.
Susan
S
Lindquist
D017360:Arabidopsis / Q000737:chemistry*; D029681:Arabidopsis Proteins / Q000737:chemistry*; D008958:Models, Molecular; D010454:Peptide Termination Factors / Q000737:chemistry; D000072002:Prion Proteins / Q000737:chemistry*; D000072417:Protein Domains; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry
D029681:Arabidopsis Proteins; C086323:LD protein, Arabidopsis; D010454:Peptide Termination Factors; D000072002:Prion Proteins; C068068:SUP35 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins
Luminidependens; plant prion domains; prions