Understanding insulin endocrinology in decapod Crustacea: molecular modelling characterization of an insulin-binding protein and insulin-like peptides in the eastern spiny lobster, Sagmariasus verreauxi
posted on 2023-05-19, 10:35authored byChandler, JC, Gandhi, NS, Mancera, RL, Gregory SmithGregory Smith, Elizur, A, Ventura, T
The insulin signalling system is one of the most conserved endocrine systems of Animalia from mollusc to man. In decapod Crustacea, such as the Eastern spiny lobster, Sagmariasus verreauxi (Sv) and the red-claw crayfish, Cherax quadricarinatus (Cq), insulin endocrinology governs male sexual differentiation through the action of a male-specific, insulin-like androgenic gland peptide (IAG). To understand the bioactivity of IAG it is necessary to consider its bio-regulators such as the insulin-like growth factor binding protein (IGFBP). This work has employed various molecular modelling approaches to represent S. verreauxi IGFBP and IAG, along with additional Sv-ILP ligands, in order to characterise their binding interactions. Firstly, we present Sv- and Cq-ILP2: neuroendocrine factors that share closest homology with Drosophila ILP8 (Dilp8). We then describe the binding interaction of the N-terminal domain of Sv-IGFBP and each ILP through a synergy of computational analyses. In-depth interaction mapping and computational alanine scanning of IGFBP_N’ highlight the conserved involvement of the hotspot residues Q67, G70, D71, S72, G91, G92, T93 and D94. The significance of the negatively charged residues D71 and D94 was then further exemplified by structural electrostatics. The functional importance of the negative surface charge of IGFBP is exemplified in the complementary electropositive charge on the reciprocal binding interface of all three ILP ligands. When examined, this electrostatic complementarity is the inverse of vertebrate homologues; such physicochemical divergences elucidate towards ligand-binding specificity between Phyla.
Funding
Australian Research Council
UTAS Nexus Aquasciences Pty Ltd
History
Publication title
International Journal of Molecular Sciences
Volume
18
Issue
9
Article number
1832
Number
1832
Pagination
1-19
ISSN
1422-0067
Department/School
Institute for Marine and Antarctic Studies
Publisher
Molecular Diversity Preservation International
Place of publication
Matthaeusstrasse 11, Basel, Switzerland, Ch-4057
Rights statement
Copyright 2017 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/