title: Molecular modelling of the TSR domain of R-spondin 4.
abstract: R-spondin 4 is a secreted protein mainly associated with embryonic nail development. R-spondins have been recently identified as heparin-binding proteins with high affinity. Proteoglycan binding has been associated with both the TSR and the C terminal basic amino acid rich domains. In this paper, molecular modelling techniques were used to construct the model of R-spondin 4 TSR domain based on the structure of the F-spondin TSR domain 4 (30-40 cent sequence identity). Beside a positively charged surface in the TSR domain, presence of the basic amino acid rich domain which could forms a continuous heparin binding surface may explain the high affinity of R-spondins for heparin. Our results provide a framework for understanding the possible regulatory role of heparin in R-spondins signalling.
authors.affiliation: Targets for Diagnosis and Therapy Centre of Biotechnology of Sfax, Sfax, Tunisia 3038. leila.ayadi@ipeis.rnu.tn
authors.forename: Leila
authors.initials: L
authors.lastname: Ayadi