A C-type lectin isolated from the skin of Japanese bullhead shark binds a remarkably broad range of sugars and induces blood coagulation
Published online on 29. November 2014
A C-type lectin isolated from the skin of Japanese bullhead shark (Heterodontus japonicus) binds a remarkably broad range of sugars and induces blood coagulation
Shigeyuki Tsutsui, Yuma Dotsuta, Ayaka Ono, Masanari Suzuki, Hiroaki Tateno, Jun Hirabayashi, Osamu Nakamura
ABSTRACT:
The aim of the present study was to determine the physiological role of skin lectins of the Japanese bullhead shark (Heterodontus japonicus). A skin extract was subjected to affinity chromatography using seven different sugars as ligands. Molecular mass and N-terminal amino acid sequence analyses indicated elution of the same protein by each of the seven respective cognate ligands from sugar affinity columns. The predicted amino acid sequence encoded by the cDNA of this protein (designated HjCL) identified it as a novel fish subgroup VII C-type lectin evolutionarily related to snake venom lectins. HjCL was predicted to bind to mannose because of the presence of a Glu-Pro-Asn (EPN) motif; however, hemagglutination inhibition assays and glycoconjugate microarray analysis demonstrated its binding to numerous structurally diverse sugars. Competitive sugar-binding assays using affinity chromatography indicated that HjCL bound multiple sugars via a common carbohydrate-recognition domain. The mRNA encoding HjCL was specifically detected in the skin, and immunohistochemical analysis detected its expression in uncharacterized large cells in the epidermis. HjCL agglutinated the bacterial pathogen Edwardsiella tarda and promoted immediate clotting of shark blood, indicating that HjCL is involved in host defense on the skin surface especially when the shark is injured and bleeds.
The Journal of Biochemistry, Advance Access, doi: 10.1093/jb/mvu080