Transcription pattern of ribosomal protein L26 during anoxia exposure in Littorina littorea

Differential screening of a hepatopancreas cDNA library derived from the ma rine snail Littorina littorea yielded a 421-bp clone coding for ribosomal p rotein L26 that was up-regulated during anoxia exposure. The deduced amino acid sequence, containing 144 residues with a predicted molecular weight of 17 kDa, showed 80% amino acid sequence identity to the mammalian ribosomal protein L26. Analysis of hepatopancreas and foot muscle samples from a tim e course of anoxia exposure showed a maximal transcript increase of 4- and 3-fold after 96 hr and 48 hr, respectively, relative to normoxic animals, w ith a subsequent decrease in transcript levels during normoxic recovery. Nu clear run-off assays confirmed the observed transcriptional up-regulation o f L26 during anoxia. Organ culture experiments were performed to determine a possible pathway of up-regulation of L26, with data indicating a putative role for cGMP in signal transduction. The transcriptional up-regulation of L26 during anoxia may stabilize the existing mRNA pool, via a possible cGM P-mediated signaling cascade, until oxygen reappears and protein synthesis resumes. J. Exp. Zool. 290:759-768, 2001. (C) 2001 Wiley-Liss, Inc.