The p38 mitogen-activated protein kinase (p38MAPK) plays a key role in larval settlement of the barnacle Amphibalanus amphitrite. To study the signaling pathway associated with p38MAPK during larval settlement, we sought to identify the upstream kinase of p38MAPK. Three MKKs (MKK3, MKK4 and MKK7) and three MAPKs (p38MAPK, ERK and JNK) in A. amphitrite were cloned and recombinantly expressed in E. coli. Through kinase assays, we found that MKK3, but not MKK4 or MKK7, phosphorylated p38MAPK. Furthermore, MKK3 activity was specific to p38MAPK, as it did not phosphorylate ERK or JNK. To further investigate the functional relationship between MKK3 and p38MAPK in vivo, we studied the localization of phospho-MKK3 (pMKK3) and MKK3 by immunostaining. Consistent with the patterns of p38MAPK and phospho-p38MAPK (pp38MAPK), pMKK3 and MKK3 mainly localized to the antennules of the cyprids. Western blot analysis revealed that pMKK3 levels, like pp38MAPK levels, were elevated at cyprid stage, compared to nauplii and juvenile stages. Moreover, pMKK3 levels increased after treatment with adult barnacle crude extracts, suggesting that MKK3 might mediate the stimulatory effects of adult barnacle extracts on the p38MAPK pathway. © 2013 Zhang et al.
|Original language||English (US)|
|State||Published - Jul 29 2013|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): SA-C0040, UK-C0016
Acknowledgements: This work was supported by a grant (DY125-15-T-02) from the China Ocean Mineral Resources Research and Development Association (http://www.comra.org), an award from the King Abdullah University of Science and Technology (SA-C0040/UK-C0016; http://www.kaust.edu.sa) and grants (GRF661611, GRF662413 and AoE/P-04/04-II) from the Research Grants Council (http://www.ugc.edu.hk/eng/rgc/index.htm) of the Hong Kong Special Administrative Region. The funders did not contribute to the experimental design, operation or manuscript writing. Additionally, the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.