National Research Institute of Fisheries Science, Kanazawa-ku, Yokohama, Kanagawa, Japan.
Ann N Y Acad Sci. 2010 Feb;1189:91-4. doi: 10.1111/j.1749-6632.2009.05181.x.
The evolutionary adaptations of functional genes to life at high pressures are not well understood. To elucidate the mechanisms of protein adaptation to high pressures, we isolated two muscle protein-encoding cDNAs, alpha-actin and myosin heavy chain (MyHC), derived from skeletal muscles of two deep-sea fishes, Coryphaenoides yaquinae and C. armatus, and two non-deep-sea fishes, C. acrolepis and C. cinereus. The alpha-actins from two deep-sea fishes have three amino acid substitutions in comparison to those of non-deep-sea fishes. These substitutions enable the deep-sea fish actins to function even at 60 MPa. The MyHCs of the two deep-sea fishes have a proline residue in the loop-1 region and have a shorter loop-2 region than the non-deep-sea fishes. Additionally, the MyHCs of deep-sea fishes have biased amino acid substitutions at core positions within the coiled-coil structure of the rod region. The roles of these substitutions in the deep-sea fishes MyHCs, however, remain unclear.
功能基因对高压环境的进化适应还不是很清楚。为了阐明蛋白质适应高压的机制，我们从两种深海鱼类（长尾鳕和短尾鳕）和两种非深海鱼类（圆鳍鱼和灰鲭鲨）的骨骼肌中分离出两种肌肉蛋白编码 cDNA，肌动蛋白和肌球蛋白重链（MyHC）。与非深海鱼类相比，两种深海鱼类的肌动蛋白有三个氨基酸取代。这些取代使深海鱼类的肌动蛋白即使在 60 MPa 的压力下也能发挥作用。两种深海鱼类的 MyHC 在 loop-1 区域有一个脯氨酸残基，并且 loop-2 区域比非深海鱼类短。此外，深海鱼类的 MyHC 在卷曲螺旋结构的核心位置有偏向性的氨基酸取代。然而，这些取代在深海鱼类 MyHC 中的作用尚不清楚。
