Identification of grass carp (Ctenopharyngodon idella) XBP1S as a primary member in ER stress.

X-box binding protein 1 (XBP1), a vital basic leucine zipper transcription factor for the related gene transcription in endoplasmic reticulum (ER) stress, belongs to the CREB/ATF family. In mammals, XBP1S is the activated one of XBP1 isoform. In order to study the role of fish XBP1S, we cloned and identified the XBP1S (KU509247) from grass carp (Ctenopharyngodon idella) (named CiXBP1S) by homologous cloning and RACE technique.

Ctenopharyngodon idella NF-κB subunit p65 modulates the transcription of IκBα in CIK cells.

NF-κB is an important transcription factor for regulating the multiple inflammatory and immune related gene transcription. It can bind with the nuclear factor κB site within the promoter of target genes to regulate their transcriptions. p65, the all-important subunit of NF-κB, is ubiquitously expressed in cells.

Grass carp (Ctenopharyngodon idella) ATF6 (activating transcription factor 6) modulates the transcriptional level of GRP78 and GRP94 in CIK cells.

ATF transcription factors are stress proteins containing alkaline area-leucine zipper and play an important role in endoplasmic reticulum stress. ATF6 is a protective protein which regulates the adaptation of cells to ER stress by modulating the transcription of UPR (Unfolded Protein Response) target genes, including GRP78 and GRP94. In the present study, a grass carp (Ctenopharyngodon idella) ATF6 full-length cDNA (named CiATF6, KT279356) has been cloned and identified.

The transcription regulation analysis of Ctenopharyngodon idellus PKR and PKZ genes.

Protein kinase R (PKR), the double-stranded RNA-activated protein kinase, exists in mammalian and fish. PKZ, a PKR-like protein kinase containing Z-DNA binding domains, just exists in fish. PKR and PKZ work synergistically in the antiviral defense by inhibiting intracellular protein translation.

Fish IRF3 up-regulates the transcriptional level of IRF1, IRF2, IRF3 and IRF7 in CIK cells.

Interferon Regulatory Factors (IRFs) belong to a family of transcription factor involved in transcriptional regulation of type I IFN and IFN-stimulated genes (ISG) in cells. In the present study, an IRF3 full-length cDNA (termed CiIRF3, JX999055) and its promoter sequence were cloned by homology cloning strategy and genome walking from grass carp (Ctenopharyngodon idella). The full-length cDNA sequence of CiIRF3 is comprised of a 5'UTR (195 bp), a 3'UTR (269 bp) and a largest open reading frame (ORF) of 1377 bp encoding a polypeptide of 458 amino acids.

A splicing isoform of Ctenopharyngodon idella ADAR1 (CiADAR1-like): Genome organization, tissue specific expression and transcriptional regulation.

Catalyzing the deamination of adenosine to inosine in RNA, ADAR1 (adenosine deaminase that act on RNA 1) belongs to ADAR family. In our previous work, we have cloned the complete genomic sequence of ADAR1 from grass carp (Ctenopharyngodon idella), named CiADAR1. In the process, we found a splicing isoform of CiADAR1 (CiADAR1-like).

Cloning, identification of the two cytokine receptor family B subunits CRFB1 and CRFB5 from grass carp (Ctenopharyngodon idella).

Similar to the mammalian counterparts, fish type I interferon (IFN) performs its potential biological activities via binding to the corresponding receptor on target cell membrane. Fish type I IFN receptor, a kind of enzyme-linked receptor, consists of two subunits and belongs to the class II cytokine receptor family B (CRFB). In the present study, we cloned and identified two putative grass carp (Ctenopharyngodon idella) type I interferon receptor subunits (termed CiCRFB1 and CiCRFB5) by homology cloning techniques.

Genome organization and transcriptional regulation of Adenosine Deaminase Acting on RNA gene 1 (ADAR1) in grass carp (Ctenopharyngodon idella).

ADAR1, involved in A-to-I RNA editing, belongs to adenosine deaminase acting on RNA (ADAR) family. A-to-I RNA editing is the most widespread editing phenomenon in higher eukaryotes. In the present study, we cloned and identified the full-length cDNA, complete genomic sequence and the promoter sequence of grass carp (Ctenopharyngodon idella) ADAR1 (CiADAR1) by homology cloning strategy and genome walking.

Ctenopharyngodon idella IRF2 plays an antagonistic role to IRF1 in transcriptional regulation of IFN and ISG genes.

Interferon Regulatory Factors (IRFs) make up a family of transcription factors involved in transcriptional regulation of type I IFN and IFN-stimulated genes (ISG) in cells. In the present study, an IRF2 gene (termed CiIRF2, JX628585) was cloned and characterized from grass carp (Ctenopharyngodon idella). The full-length cDNA of CiIRF2 is 1809 bp in length, with the largest open reading frame (ORF) of 981 bp encoding a putative protein of 326 amino acids.

Promoter analysis and transcriptional regulation of a Gig2 gene in grass carp (Ctenopharyngodon idella).

Grass carp reovirus (GCRV)-induced gene 2 (Gig2) is recognized as a new antiviral factor involved in response to viral infection. However, little is known about the mechanisms behind the transcriptional regulation of Gig2 when infected by virus. In this study, the upstream promoter region of grass carp (Ctenopharyngodon idella) Gig2 gene (CiGig2) was identified by homology cloning strategy.

SiRNA-mediated knockdown of CiGRP78 gene expression leads cell susceptibility to heavy metal cytotoxicity.

Heavy metal ion is one of the critical environmental pollutants accumulated in living organisms and causes toxic or carcinogenic effects once passed threshold levels. As an important member of Hsp70 (heat shock protein 70) family, the 78-kDa glucose-regulated protein (GRP78) can enhance cell survival rates remarkably under thermal stress. Recent studies also demonstrated that the expression of GRP78 enhances the cell survival under heavy metal stress.

ATF4 (activating transcription factor 4) from grass carp (Ctenopharyngodon idella) modulates the transcription initiation of GRP78 and GRP94 in CIK cells.

GRP78 and GRP94, belong to GRP (glucose-regulated protein) family of endoplasmatic reticulum (ER) chaperone superfamily, are essential for cell survival under ER stress. ATF4 is a protective protein which regulates the adaptation of cells to ER stress by modulating the transcription of UPR (Unfolded Protein Response) target genes, including GRP78 and GRP94. To understand the molecular mechanism of ATF4 modulates the transcription initiation of CiGRP78 and CiGRP94, we cloned ATF4 ORF cDNA sequences (CiATF4) by homologous cloning techniques.