Genetic knockout and general odorant binding/chemosensory proteins
interactions: revealed the function and importance of GOBP2 in the
yellow peach moth olfactory system
Abstract
The GOBP2 protein has a unique function in the yellow peach moth,
Conogethes punctiferalis. Several general odorant binding proteins
(GOBPs) have been identified in various lepidopteran species, but the
functional difference between GOBP1 and GOBP2 in recognition of host
plant odorants is still unknown. The functions of GOBP1 and GOBP2 in the
yellow peach moth were evaluated in this study using the CRISPR-Cas9
system. The results revealed the importance of GOBP2 in the olfaction
mechanism in the yellow peach moth. The GOBP1 knocked out larvae’s
perception towards feeding decreased but did not reach a significant
level, while knocking out the GOBP2 and GOBP1/2 genes resulted in huge
differences. On the other hand, electroantennograms (EAG) and wind
tunnel tests showed that the GOBP2 knocked out adult’s sensitivity to
odorants decreased more than GOBP1 knocked out individuals. The STRING
database text mining results grabbed our attention in the
protein-protein interaction studies. In this research, we firstly proved
the existence of physical interactions between GOBPs and chemosensory
proteins (CSP) through the surface plasmon resonance (SPR) and
isothermal titration calorimetry (ITC) methods. Interestingly, the GOBP1
and GOBP2 could not interact with each other, but they can interact with
CSPs. The interaction result indicates that GOBP2 could physically
interact with CSP15, CSP5, and OBP17, whereas GOBP1 could bind only with
CSP5 and CSP10, and the association constant (ka) is also more
substantial than GOBP1. These results strongly suggest the importance of
GOBP2 function in the perception of host plants odorants in the yellow
peach moth.