Targeted knock-down of a structurally atypical zebrafish 12S-lipoxygenase leads to severe impairment of embryonic development
- Authors
- Haas, U., Raschperger, E., Hamberg, M., Samuelsson, B., Tryggvason, K., and Haeggström, J.Z.
- ID
- ZDB-PUB-111207-10
- Date
- 2011
- Source
- Proceedings of the National Academy of Sciences of the United States of America 108(51): 20479-84 (Journal)
- Registered Authors
- Raschperger, Elisabeth
- Keywords
- 12-lipoxygenase, stereospecificity
- MeSH Terms
-
- Animals
- Arachidonate 12-Lipoxygenase/chemistry*
- Arachidonate 12-Lipoxygenase/genetics
- Arachidonic Acid/chemistry
- Blood Platelets/metabolism
- Chromatography, High Pressure Liquid/methods
- Chromatography, Liquid/methods
- Cloning, Molecular
- Developmental Biology/methods
- Gene Expression Profiling
- Gene Expression Regulation, Developmental*
- Immunohistochemistry/methods
- Mass Spectrometry/methods
- Microscopy, Fluorescence/methods
- Phenotype
- Stereoisomerism
- Zebrafish
- PubMed
- 22143766 Full text @ Proc. Natl. Acad. Sci. USA
Lipoxygenases (LO) are a class of dioxygenases, which form hydroperoxy, hydroxy, and epoxy derivatives of arachidonic acid with distinct positional and stereochemical configurations. In man, there are two known types of 12-LO that are distinguished by their expression patterns and catalytic properties. The platelet 12S-LO plays a role in platelet aggregation and 12R-LO seems to be important for normal skin function. Using BLAST searches of the zebrafish (zf) genome we identified one candidate zf12-LO gene with 43% identity with human 12R-LO at the mRNA level and the deduced primary sequence carried the so called “Coffa” structural determinant (Gly residue) for R stereoselectivity of LOs. However, incubations of recombinant, purified, zf12-LO with arachidonic acid revealed exclusive formation of 12(S)-hydroperoxy-eicosatetraenoic acid. Further studies with immunohistochemistry showed prominent expression of zf12-LO in the cell nuclei of skin epithelium, the epithelial lining of the stomodeum, and the pharyngeal pouches in zf embryos. To probe its function, zf12-LO was subjected to targeted knock-down in zf embryos, resulting in the development of a severe phenotype, characterized by abnormal development of the brain, the eyes, and the tail as well as pericardial and yolk sac edema. Hence, we have identified a unique vertebrate 12S-LO that breaks the current structure-function paradigms for S and R stereo-specificity and with critical roles in normal embryonic development.