title: Molecular characterization and expression analysis of three membrane-bound complement regulatory protein isoforms in the ginbuna crucian carp Carassius auratus langsdorfii.
abstract: Regulators of complement activation (RCA) play a role in protecting cells from excessive complement activation in humans. cDNA corresponding to three isoforms of teleost membrane-bound RCA protein (gTecrem) have been identified in the ginbuna crucian carp. gTecrem-1 consists of seven short consensus repeats (SCRs), whereas gTecrem-2 and gTecrem-3 have four SCRs. While gTecrem-1 possesses a tyrosine phosphorylation site in its cytoplasmic region, gTecrem-2 and gTecrem-3 lack the site. Tissue distribution analysis showed that gTecrem-1 and gTecrem-2 mRNAs were expressed in almost all tissues examined, whereas gTecrem-2 expression was not significantly detected in gill, liver, or intestine. Furthermore, analysis showed that gTecrem-1 was expressed in both peripheral blood leukocytes (PBLs) and erythrocytes and was also expressed in T cell subsets such as CD4(+), CD8(+) T cells, and IgM(+) B cells. gTecrem-2 expression was not detected in either PBLs or erythrocytes, whereas gTecrem-3 was expressed only in erythrocytes. These results suggested that gTecrem isoforms may serve different functional roles; gTecrem-1, which is expressed in T cells and possesses a tyrosine phosphorylation site, may act as a complement regulator and a cellular receptor in adaptive immunity.
authors: Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.
authors: Indriyani
authors: I
authors: Nur
authors: Hikari
authors: H
authors: Harada
authors: Masakazu
authors: M
authors: Tsujikura
authors: Tomonori
authors: T
authors: Somamoto
authors: Miki
authors: M
authors: Nakao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002347:Carps / Q000235:genetics* / Q000378:metabolism; D003165:Complement System Proteins / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D009928:Organ Specificity; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D003165:Complement System Proteins
keywords: Ginbuna crucian carp; Isoform; Membrane-bound complement regulatory protein; Short consensus repeats; Teleost