tailieunhanh - Báo cáo khoa học: Differential expression of duplicated LDH-A genes during temperature acclimation of weatherfish Misgurnus fossilis Functional consequences for the enzyme

Temperature acclimation in poikilotherms entails metabolic rearrangements provided by variations in enzyme properties. However, in most cases the underlying molecular mechanisms that result in structural changes in the enzymes are obscure. | ỊFEBS Journal Differential expression of duplicated LDH-A genes during temperature acclimation of weatherfish Misgurnus fossilis Functional consequences for the enzyme Maxim Zakhartsev1 2 Magnus Lucassen1 Liliya Kulishova2 Katrin Deigweiher1 Yuliya A. Smirnova3 Rina D. Zinov eva3 Nikolay Mugue3 Irina Baklushinskaya3 Hans O. Portner1 and Nikolay D. Ozernyuk3 1 Alfred Wegener Institute for Polar and Marine Research Bremerhaven Germany 2 InternationalUniversity Bremen Germany 3 Kol tsov Institute of DevelopmentalBiology RAS Moscow Russia Keywords lactate dehydrogenase mRNA paralogs protein function temperature acclimation Correspondence M. Zakhartsev Marine AnimalPhysiology Alfred Wegener Institute for Polar and Marine Research AWI Am Handelshaven 12 27570 Bremerhaven Germany Fax 49 471 4831 1149 Tel 49 471 4831 1381 E-mail Received 9 November 2006 revised 10 January 2007 accepted 12 January 2007 doi Temperature acclimation in poikilotherms entails metabolic rearrangements provided by variations in enzyme properties. However in most cases the underlying molecular mechanisms that result in structural changes in the enzymes are obscure. This study reports that acclimation to low 5 C and high 18 C temperatures leads to differential expression of alternative forms of the LDH-A gene in white skeletal muscle of weatherfish Misgurnus fossilis. Two isoforms of LDH-A mRNA were isolated and characterized a short isoform mRNÁjđh_a 1332 bp and a long isoform mRNÁỊđh_a 1550 bp which both have 5 -UTRs and ORFs of the same length 333 amino acid residues but differ in the length of the 3 -UTR. In addition these two mRNAs have 44 nucleotide point mismatches of an irregular pattern along the complete sequence resulting in three amino acid mismatches Gly214Val Val304Ile and Asp312Glu between protein products from the short and long mRNA forms correspondingly LDH-Aa and LDH-Ab subunits. It is expected that the b-subunit is more .