RT Journal Article
SR Electronic
T1 Nematode germ granule assembly is linked to mRNA repression
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 382838
DO 10.1101/382838
A1 Scott Takeo Aoki
A1 Sarah L Crittenden
A1 Tina R Lynch
A1 Craig A Bingman
A1 Marvin Wickens
A1 Judith Kimble
YR 2018
UL http://biorxiv.org/content/early/2018/08/01/382838.abstract
AB RNA-protein (RNP) granules are non-membrane bound organelles with enigmatic roles in RNA metabolism. Metazoa contain RNP “germ granules” specialized for germline development. Caenorhabditis elegans P-granules are liquid droplet germ granules that require PGL proteins for assembly. Here we investigate PGL proteins to understand the relationship between P-granule assembly and germline function. We determine the crystal structure of a PGL N-terminal domain (NTD) and find that it dimerizes. From the structure, we identify mutations that disrupt PGL dimerization in vitro and prevent PGL granule formation in mammalian cells in culture. These same mutations in nematodes prevent assembly of PGL into P-granules and cause sterility. Using a protein-mRNA tethering assay, we show that mRNAs recruited to PGL-1 are repressed, while mRNAs recruited to PGL-1 mutants defective for granule assembly are expressed. Therefore, the effects of PGL on mRNA repression and fertility are tightly linked to its formation of higher-ordered assemblies.AbbreviationsRNAribonucleic acidUTRuntranslated regionGFPgreen fluorescent proteinCRISPRClustered Regularly Interspaced Short Palindromic Repeats