title: Molecular identification and expression analysis of a natural killer cell enhancing factor (NKEF) from rock bream Oplegnathus fasciatus and the biological activity of its recombinant protein.
abstract: Natural killer cell enhancing factor (NKEF) belongs to the defined peroxiredoxin (Prx) family. Rock bream NKEF cDNA was identified by expressed sequence tag (EST) analysis of rock bream liver that was stimulated with the LPS. The full-length RbNKEF cDNA (1062 bp) contained an open reading frame (ORF) of 594 bp encoding 198 amino acids. RbNKEF was significantly expressed in the gill, liver, and intestine. mRNA expression of NKEF in the head kidney was examined under viral and bacterial challenge via real-time RT-PCR. Experimental challenge of rock bream with Edwardsiella tarda, Streptococcus iniae, and RSIV resulted in significant increases in RbNKEF mRNA in the head kidney. To obtain a recombinant NKEF, the RbNKEF ORF was expressed in Escherichia coli BL21 (DE3), and the purified soluble protein exhibited a single band corresponding to the predicted molecular mass. When kidney leucocytes were treated with a high concentration of rRbNKEF (10 μg/mL), they exhibited significantly enhanced cell proliferation and viability under oxidative stress.
authors.affiliation: Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 455, Tongyeong 650-160, Republic of Korea.
authors.forename: Ju-Won
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Pathology Division, National Fisheries Research and Development Institute, Busan 619-900, Republic of Korea.
authors.forename: Hye-Sung
authors.initials: HS
authors.lastname: Choi
authors.affiliation: Pathology Division, National Fisheries Research and Development Institute, Busan 619-900, Republic of Korea.
authors.forename: Mun-Gyeong
authors.initials: MG
authors.lastname: Kwon
authors.affiliation: Pathology Division, National Fisheries Research and Development Institute, Busan 619-900, Republic of Korea.
authors.forename: Myoung-Ae
authors.initials: MA
authors.lastname: Park
authors.affiliation: Pathology Division, National Fisheries Research and Development Institute, Busan 619-900, Republic of Korea.
authors.forename: Jee-Youn
authors.initials: JY
authors.lastname: Hwang
authors.affiliation: Department of Aqualife Medicine, Chonnam National University, San 96-1, Dun-Duk Dong, Yeosu, Republic of Korea ; Fish Health Center, Chonnam National University, San 96-1, Dun-Duk Dong, Yeosu, Republic of Korea.
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 455, Tongyeong 650-160, Republic of Korea.
authors.forename: Chan-Il
authors.initials: CI
authors.lastname: Park
keywords: NKEF; Oxidative stress; Peroxiredoxin; Rock bream