ABSTRACT G protein‐coupled receptor kinases (GRKs) are key regulators of G protein‐coupled receptor signaling, but the role of GRK2 in insect metamorphic development remains incompletely understood. This study investigated the function of HvGRK2 in the agarwood pest Heortia vitessoides . HvGRK2 was identified and cloned from H. vitessoides . Developmental and tissue‐specific expression patterns were analyzed by RT‐qPCR. Transcriptional responses of HvGRK2 to exogenous 20‐hydroxyecdysone (20E) injection and tebufenozide treatment were examined. RNA interference (RNAi) was used to assess the function of HvGRK2 during metamorphosis, and the expression of 20E‐responsive genes and hemolymph 20E titer were subsequently measured. HvGRK2 showed stage‐ and tissue‐specific expression, with elevated transcript levels in late larval instars and a peak at the pre‐pupal stage. HvGRK2 expression was enriched in the larval gut and fat body. Exogenous 20E induced a dynamic transcriptional response of HvGRK2 , and tebufenozide treatment caused dose‐dependent changes in HvGRK2 expression. RNAi‐mediated knockdown of HvGRK2 reduced larval body weight, increased mortality, and caused pupation failure and adult deformities. Knockdown of HvGRK2 also reduced the expression of the 20E‐responsive genes E75 , HR3 , and HR4 , whereas USP showed no significant change. In addition, hemolymph 20E titer decreased at 24 h after dsHvGRK2 injection. These findings provide a basis for understanding the role of HvGRK2 in endocrine‐associated development in this species.
Sun et al. (Fri,) studied this question.