Meeting Abstract
P1.139 Sunday, Jan. 4 Multiple isoforms of Late Embryogenesis Abundant proteins in Artemia franciscana embryos. BOSWELL, L.C.*; MENZE, M.A.; HAND, S.C.; Louisiana State University, Baton Rouge; Louisiana State University, Baton Rouge; Louisiana State University, Baton Rouge lboswe1@lsu.edu
Late Embryogenesis Abundant (LEA) proteins are highly hydrophilic, low complexity proteins whose expression has been correlated with desiccation tolerance in anhydrobiotic organisms. Originally discovered in plants, LEA proteins have also been identified in bacteria, cyanobacteria, fungi, nematodes, brine shrimp, and a chironomid insect larva. We have currently identified and sequenced six LEA genes in embryos of the brine shrimp Artemia franciscana. The deduced amino acid sequence of one protein (AfrLEA3m) is predicted to be mitochondrially localized by subcellular targeting programs. Bioinformatic analysis of these six proteins has shown each to contain qualities indicative of a group 3 LEA protein including strong hydrophilicity, and prediction of high alpha-helix content. Two of the Afrlea genes have been successfully cloned into a bacterial expression system and one protein isoform has been overexpressed and purified. Furthermore RT-qPCR has been performed on three of the six AfrLEA mRNAs. This analysis has revealed the mRNA expression of all three to be several fold higher in the two embryonic stages of A. franciscana that possess desiccation tolerance, when compared to the desiccation-intolerant nauplius larva. Verification of the predicted mitochondrial location of AfrLEA3m has also been accomplished, which represents the first evidence of a LEA protein targeted to mitochondria of animals. A nucleotide construct encoding the first seventy N-terminal amino acids of AfrLEA3m was ligated to the nucleotide sequence for green fluorescent protein (GFP) and transiently transfected into human hepatoma cells (HepG2/C3A). As confirmed with confocal imaging, the expressed fusion protein was imported into mitochondria. [NIH grant 2 RO1 DK046270-14A1]
