Biochemical Characterization of Three BLT Receptors in Zebrafish
- Authors
- Okuno, T., Ishitani, T., Yokomizo, T.
- ID
- ZDB-PUB-150305-1
- Date
- 2015
- Source
- PLoS One 10: e0117888 (Journal)
- Registered Authors
- Ishitani, Tohru
- Keywords
- Zebrafish, Embryos, Sequence alignment, Sequence motif analysis, CHO cells, Molting, Messenger RNA, Morpholino
- MeSH Terms
-
- Amino Acid Sequence
- Animals
- Molecular Sequence Data
- Protein Binding
- Receptors, Leukotriene B4/chemistry*
- Receptors, Leukotriene B4/genetics
- Receptors, Leukotriene B4/metabolism
- Zebrafish
- Zebrafish Proteins/chemistry*
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
- PubMed
- 25738285 Full text @ PLoS One
The leukotriene B4 (LTB4) receptor 1 (BLT1) is a high affinity receptor for LTB4, a chemotactic and inflammatory eicosanoid. The LTB4 receptor 2 (BLT2) was originally identified as a low affinity receptor for LTB4, and, more recently, as a high affinity receptor for 12-hydroxyheptadecatrienoic acid (12-HHT). The zebrafish BLT receptors have not been previously identified and the in vivo functions of these receptors have been unknown. In this paper, we describe one zebrafish BLT1-like receptor, Blt1, and two zebrafish BLT2-like receptors, Blt2a and Blt2b. Cells expressing Blt1 exhibited LTB4-induced intracellular [Ca2+] increases, inhibition of cAMP production, ligand-dependent [35S]GTPγS binding, and transforming growth factor-α (TGFα) shedding activity in a dose-dependent manner, similar to human BLT1. Cells expressing Blt2a and Blt2b exhibited 12-HHT- and LTB4-induced intracellular [Ca2+] increases, inhibition of cAMP production, [35S]GTPγS binding, and TGFα shedding activity, with a dose-dependency similar to human BLT2. Reverse transcription (RT)-PCR analysis and whole-mount in situ hybridization revealed that blt1, blt2a, blt2b, zebrafish LTA4 hydrolase (lta4h), and zebrafish 5-lipoxiganase (5lo) are expressed in zebrafish embryos. Knockdown of blt1 by morpholino antisense oligonucleotides resulted in delayed epiboly at gastrulation. Consistently, knockdown of lta4h, an enzyme mediating LTB4 production, induced a phenotype similar to knockdown of blt1. These results suggest that the LTB4-BLT1 axis is involved in epiboly in zebrafish development.