Identification of a granulin-like transcript expressed during anoxic exposure and translated during aerobic recovery in a marine gastropod.
A novel transcript encoding a cysteine-rich granulin-like peptide (l-grn) was identified in the hepatopancreas of the marine intertidal gastropod, Littorina littorea, an anoxia-tolerant species. Experimental exposure of snails to anoxia induced a gradual accumulation of l-grn transcripts over time, with expression regulated in vitro through elements responsive to second messengers of protein kinases A, C and G. Translation of this transcript was analyzed by examining l-grn association with ribosomes during normoxia, anoxia, and aerobic recovery. Transcripts of l-grn were associated with polysomes during normoxia, moved into the monosome fractions under anoxia, but shifted back to the polysomal fractions during aerobic recovery. Western blotting confirmed this with a granulin-like protein detected under normoxic conditions, but not during anoxia exposure. A significant increase in the precursor protein and peptide (L-GRN) was observed during the aerobic recovery period. The accumulation of l-grn transcripts during anoxic exposure and subsequent translation following the return to aerobic conditions may be a response to oxidant damage that occurs during re-oxygenation. Overall, the data show that the l-grn gene is anoxia-responsive in this species and may have pro-survival functions during the recovery period.
Larade
Kevin
K
Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada.
Storey
Kenneth B
KB
D000595:Amino Acid Sequence; D000818:Animals; D000860:Hypoxia / Q000235:genetics*; D036341:Intercellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics*; D008386:Marine Biology; D008969:Molecular Sequence Data; D008974:Mollusca / Q000235:genetics*; D000077153:Progranulins; D012333:RNA, Messenger / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D036341:Intercellular Signaling Peptides and Proteins; D000077153:Progranulins; D012333:RNA, Messenger