Comparative sequence analysis of myosin heavy chain proteins from congeneric shallow- and deep-living rattail fish (genus Coryphaenoides)

Abstract

SUMMARYThe evolutionary adaptations of functional genes to life at high pressure are not well understood. To elucidate the mechanisms of protein adaptation to high pressure, we cloned the myosin heavy chain (MyHC) cDNA from skeletal muscle of two deep-sea fishes, Coryphaenoides yaquinae and C. armatus, and two non-deep-sea fishes, C. acrolepis and C. cinereus. The MyHCs of deep-sea fishes have a unique structure in two loop regions, loop-1 and loop-2, in comparison with those of non-deep-sea fishes. The loop-1 region of deep-sea fishes has a Pro residue and the loop-2 region, which is an actin-binding site, is shorter than the same region in non-deep-sea fishes. The amino acid substitution in the loop-1 region is expected to be mainly involved in ATPase activity, whereas the deletion in the loop-2 region affects the association of MyHC with actin filaments at high pressure. In addition, the MyHC of deep-sea fishes has biased amino acid substitutions at core positions in the coiled-coil structure of the rod region. These amino acid substitutions are likely to decrease the cavities in the coiled-coil structure and consequently make the structure more compact and unaffected by high pressure. Together, these results indicate that amino acid substitutions can adaptively alter the pressure sensitivity of a protein even if they do not directly influence core structure.

Mechanism of Deep-Sea Fish α-Actin Pressure Tolerance Investigated by Molecular Dynamics Simulations

“…Although the pressure of the deep-sea habitat is below the actin denaturation pressure, pressure has significant effects on polymerization and the dissociation rates of ATP and Ca 2+ in non-deep-sea fish actins, whereas the actins of deep-sea fish are tolerant of pressures up to at least 60 MPa [10], [15]. In this work, we investigated the effect of the amino acid substitutions on pressure tolerance using MD simulations.…”

“…At high pressure, protein denaturation, conformational changes, and loss of enzymatic activity are observed [10], [13], [14], [15]. The ligand dissociation rates of hydrolases and dehydrogenases were shown to increase at high pressure [10], [16], [17].…”

Molecular adaptation in the world's deepest‐living animal: Insights from transcriptome sequencing of the hadal amphipod Hirondellea gigas

“…Recent studies of fishes indicate that amino acid substitutions help proteins maintain their 3D structures, thus maintaining their functions in the deep sea (Morita, , ). On the other hand, osmolytes, small cellular molecules that function as protein stabilizers, can strengthen the structure of proteins in deep‐sea animals.…”

cDNA cloning and expression analysis of the myosin heavy chain (MYH) gene of the mandarin fishSiniperca kneri

“…MyHC binding of F‐actin functions as a molecular motor by tansducing chemical energy from ATP hydrolysis into mechanical work (Spudich 1994). The cDNA domains of MyHCs in fish from different water invironment varies to adapt different water pressure by changing of the length of terminal loops and amino‐acid substitution (Morita 2008). The MyHC DNA sequences from Antarctic fish contained similar domains but short in loop‐1 region (Gauvry, Ennion, Ettelaie & Goldspink 2000).…”

“…The MyHC DNA sequences from Antarctic fish contained similar domains but short in loop‐1 region (Gauvry, Ennion, Ettelaie & Goldspink 2000). In this study, the Madarin fish, S. keneri is a lower level of water of fish and its ATP‐binding and acitin‐binding domains of the MYH gene exhibits relatively high homology to deep‐water counterparts (Morita 2008).…”