title: Characterization and function of CREB homologue from Crassostrea ariakensis stimulated by rickettsia-like organism.
abstract: The cAMP response element-binding protein (CREB) is a transcription factor that plays important roles in cellular growth, proliferation and survival. Here, we report that a homologue of CREB transcription factor, Ca-CREB, was identified and functionally characterized in oyster, Crassostrea ariakensis. The full-length cDNA consists of 1397bp with an ORF encoding a 39.3kDa protein. Amino acid sequence analysis revealed that Ca-CREB shares conserved signature motifs with other CREB proteins. Ca-CREB was ubiquitously and constitutively expressed in oyster, and the expression level in hemocytes was higher than that in other tissues. The expression level of Ca-CREB was not modified after RLO stimulation, while tumor necrosis factor-alpha (TNF-alpha) expression was increased obviously, which was revealed by real-time reverse-transcriptase polymerase chain reaction (RT-PCR). Electrophoretic mobility shift assay (EMSA) and Western blotting showed that recombinant CREB proteins specifically bind the consensus CREB binding site, and DNA-binding activity and phosphorylation of Ca-CREB were induced by RLO. These results suggest that Ca-CREB is a CREB homologue and may be involved in immune responses against RLO.
authors.affiliation: Laboratory of Marine Life Science and Technology, College of Animal Sciences, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029, PR China.
authors.forename: Baojian
authors.initials: B
authors.lastname: Zhu
authors.forename: Xinzhong
authors.initials: X
authors.lastname: Wu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D049896:Crassostrea / Q000737:chemistry / Q000276:immunology* / Q000382:microbiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D051381:Rats; D012281:Rickettsia / Q000276:immunology*; D017422:Sequence Analysis, DNA
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein