Zoological Studies

Vol. 54, 2015

Proteomic study of the brackish water mussel Mytilopsis leucophaeata

Feico MAH Schuurmans Stekhoven1*, Gerard van der Velde1,4, Tsung-Han Lee2 and Andrew R Bottrill3

1Department of Animal Ecology and Ecophysiology, Faculty of Science, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
2Department of Life Sciences, National Chung-Hsing University, Taichung 402, Taiwan
3Protein and Nucleic Acid Chemistry Laboratory, Proteomics Facility, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
4Naturalis Biodiversity Center, P.O. Box 9517,2300RA Leiden, The Netherlands

Background: We encountered the opportunity to study proteochemically a brackish water invertebrate animal, Mytilopsis leucophaeata, belonging to the bivalves which stem from the second half of the Cambrian Period (about 510 million years ago). This way, we were able to compare it with the vertebrate animal, the frilled shark (Chlamydoselachus anguineus) that stems from a much later period of geologic time (Permian: 245–286 MYA).
Results: The mussel contains a well-adapted system of protein synthesis on the ER, protein folding on the ER, protein trafficking via COPI or clathrin-coated vesicles from endoplasmic reticulum (ER) to Golgi and plasmalemma, an equally well-developed system of actin filaments that with myosin forms the transport system for vesicular proteins and tubulin, which is also involved in ATP-driven vesicular protein transport via microtubules or transport of chromosomes in mitosis and meiosis. A few of the systems that we could not detect in M. leucophaeata in comparison with C. anguineus are the synaptic vesicle cycle components as synaptobrevin, cellubrevin (v-snare) and synaptosomal associated protein 25-A (t-snare), although one component: Ras-related protein (O-Rab1) could be involved in synaptic vesicle traffic. Another component that we did not find in M. leucophaeata was Rab11 that is involved in the tubulovesicular recycling process of H+/K
+-ATPase in C. anguineus. We have not been able to trace the H+/K+-ATPase of M. leucophaeata, but Na+/K+-ATPase was present. Furthermore, we have studied the increase of percent protein expression between 1,070 MYA (the generation of the Amoeba Dictyostelium discoideum) and present (the generation of the mammal Sus scrofa = wild boar). In this time span, three proteomic uprises did occur: 600 to 500 MYA, 47.5 to 4.75 MYA, and 1.4 to 0 MYA. The first uprise covers the generation of bivalves, the second covers gold fish, chicken, brine shrimp, house mouse, rabbit, Japanese medaka and Rattus norvegicus, and the third covers cow, chimpanzee, Homo sapiens, dog, goat, Puccinia graminis and wild boar. We hypothesise that the latter two uprises are related to geological and climate changes and their compensation in protein function expression.
Conclusions: The proteomic and evolutionary data demonstrate that M. leucophaeata is a highly educatioanal animal to study.

Key words: Mytilopsis leucophaeata; Proteomics; Localisation; Function and adaptation periods.

*Correspondence: E-mail: F.Stekhoven@gmail.com