The DEAD Box RNA Helicase VBH-1 Is a New Player in the Stress Response in <i>C. elegans</i>

<div><p>For several years, DEAD box RNA helicase Vasa (DDX4) has been used as a bona fide germline marker in different organisms. <i>C. elegans</i> VBH-1 is a close homolog of the Vasa protein, which plays an important role in gametogenesis, germ cell survival and embryonic development. Here, we show that VBH-1 protects nematodes from heat shock and oxidative stress. Using the germline-defective mutant <i>glp-4(bn2)</i> we found that a potential somatic expression of <i>vbh-1</i> might be important for stress survival. We also show that the VBH-1 paralog LAF-1 is important for stress survival, although this protein is not redundant with its counterpart. Furthermore, we observed that the mRNAs of the heat shock proteins <i>hsp-1</i> and <i>sip-1</i> are downregulated when <i>vbh-1</i> or <i>laf-1</i> are silenced. Previously, we reported that in <i>C. elegans</i>, VBH-1 was primarily expressed in P granules of germ cells and in the cytoplasm of all blastomeres. Here we show that during stress, VBH-1 co-localizes with CGH-1 in large aggregates in the gonad core and oocytes; however, VBH-1 aggregates do not overlap with CGH-1 foci in early embryos under the same conditions. These data demonstrate that, in addition to the previously described role for this protein in the germline, VBH-1 plays an important role during the stress response in <i>C. elegans</i> through the potential direct or indirect regulation of stress response mRNAs.</p>