Adhesive Protein cDNA Sequence of the Mussel Mytilus coruscus and Its Evolutionary Implications

Abstract

Abstract. cDNA encoding the adhesive protein of the mussel Mytilus coruscus (Mcfpl) was isolated. The coding region encoded 848 amino acids (a.a.) comprising the 20-a.a. signal peptide, the 21-a.a. nonrepetitive linker, and the 805-a.a. repetitive domain. Although the first 204 nucleotides and the 3'-untranslated region of Mcfpl eDNA were homologous to corresponding parts of M. galloprovincialis adhesive protein (Mgfpl) eDNA, the other parts diverged. The representative repeat motif of the repetitive domain, YKPK(I/P)(S/T)YPP(T/S), was similar but slightly different from the repeat motif of Mgfpl. The codon usage patterns for the same amino acids were different in different positions of the decapeptide motif. Almost identical nucleotide sequences encoding the two to 13 repeats appeared several times in the repetitive region, which suggests that the adhesive protein genes of mussels have evolved through the duplication of these repeat units.

Expression of a model peptide of a marine mussel adhesive protein in Escherichia coli and characterization of its structural and functional properties

“…29,30 So hydroxyration of amino acids may be also important, although the specific function of this protein is unclear. Genetic analysis of this protein suggested the gene duplication or diversity 31,32 and the specifity of the tissue of expression. 33,34 These results can clarify not only the relationships among the mussels, but also the mechanism of their adhesion.…”

Stiff Coatings on Compliant Biofibers: The Cuticle of Mytilus californianus Byssal Threads,

“…Apart from switching the Pro from one side of Lys-2 to the other, introduction of highly hydrophobic Ile into the decapeptide sequence is noteworthy, given that after post-translational modification, all the other residues become quite polar. The cDNA-deduced sequence of a homologue from an Asian species, M. coruscus , shows a similar placement of Ile in the consensus sequence as in mcfp-1, but no other details are known about this protein (36). An intriguing difference between mcfp-1 (variant 1) and the mfp-1s of other mussels is a mass discrepancy of about 4 kDa between the virtual mass (cDNA-deduced protein sequence) and the observed mass after adjusting for all known hydroxylations.…”

Super-motifs and evolution of tandem leucine-rich repeats within the small proteoglycans?biglycan, decorin, lumican, fibromodulin, PRELP, keratocan, osteoadherin, epiphycan, and osteoglycin

“…61 Many proteins other than those with LRRs have super-repeats of tandem repeat units. Examples include nebulin, 62 titin/connectin, 63 mucin, 64 spectrin, 65 adhesive protein of mussles, 66 kininogens, 67 ice nucleation proteins, 68,69 and certain zinc finger proteins. 70 We analyzed the LRR regions of these small proteoglycans in greater detail first to understand the character, number, and phasing of the LRRs.…”