Identification and Expression Profiles of IL-8 in Bighead Carp (Aristichthys nobilis) in Response to Microcystin-LR

摘要

Chemokines are a family of small cytokines secreted by cells (Laing and Secombes 2004). The CXC chemokines are the principal group in the chemokine family, which can be subdivided into two categories, those with an glutamate (E)-leucine (L)-arginine (R) motif (ELR-positive) and those without the motif (ELR-negative) (Fernandez and Lolis 2002). Interleukin-8 (IL-8) is a member of the CXC chemokine family that can be produced by a wide variety of cells in response to many stimulants. IL-8 is synthesized as a precursor with a signal peptide, which is proteolytically processed to release an 8-kD molecule (Harun et al. 2008). The active form of IL-8 is a dimmer and is comprised of two identical subunits. IL-8 monomer contains a triple-strand antiparallel (3-sheet, whereas the dimer comprises a six-strand antiparallel ^-pleated sheet and is spanned by two long symmetry-related a-helices, which locate in the car-boxy terminal of the two subunits (Clore et al. 1990).