Aquaculture Reports (Nov 2021)
Molecular characterization of a c-Jun NH2-terminal kinase (JNK)-interacting protein 4 (Lv-JIP4) in Litopenaeus vannamei and its potential role in the Lv-p38MAPK pathway in response to low temperature
Abstract
C-Jun NH2-terminal kinase (JNK)-interacting protein 4 (JIP4) is an essential molecule that organizes and links components of the mitogen-activated protein kinase (MAPK) pathway. In the present study, a novel JIP4 gene was identified in Litopenaeus vannamei and designated Lv-JIP4. The full-length Lv-JIP4 cDNA was 3923 bp in length and contained a 170-bp 5′-untranslated region (UTR), a 72-bp 3′-UTR, and a 3,681-bp open reading frame (ORF). The Lv-JIP4 protein contained three functional domains, including the Jnk-SapK_ap_N, JIP_LZII and WD40 domains. Lv-JIP4 mRNA was broadly distributed in all studied tissues, with the highest level in muscle. The in situ hybridization results showed that the Lv-JIP4 was scattered in muscle fibres and near the sarcolemma. Subcellular localization analysis indicated that Lv-JIP4 was located in the cytoplasm but not in the nucleus. The transcript levels of Lv-JIP4 in muscle were found to be significantly increased by low temperature, low pH, high salinity, poly(I:C), and LPS challenges, indicating that it might play a crucial role in responding to adverse stresses. The transcript levels of Lv-JIP4, Lv-p38aMAPK and Lv-p38bMAPK in muscle were significantly upregulated after challenge with low temperature, suggesting that Lv-JIP4 may be the positive regulator of Lv-p38aMAPK and Lv-p38bMAPK under low temperature stress conditions. In addition, after knockdown of Lv-JIP4 expression, the protein levels of total Lv-p38MAPK and phospho-Lv-p38MAPK in the experimental dsRNA group were attenuated compared with those in the control group after 48 h (h), 60 h and 72 h of low-temperature stress, indicating that it might activate and phosphorylate the Lv-p38MAPK protein in response to cold stress. Here, we elucidated the molecular characteristics and the potential role of Lv-JIP4 and further refined the signal transduction mechanism of L. vannamei in response to low-temperature stress.
