Insights into cyclotide evolution from transcriptomic analyses and studies on their distribution in violets
(English)Manuscript (preprint) (Other academic)
Cyclotides are a family of plant-derived proteins that are characterized by a cyclic backbone and a knotted disulfide topology. Their cyclic cystine knot (CCK) motif makes them exceptionally resistant to thermal, chemical, and enzymatic degradation. Cyclotides exert much of their biological activity via interactions with cell membranes. In this work, we explore cyclotide evolution by sequencing and analyzing the transcriptomes of Viola albida var. takahashii, V. mandshurica, V. orientalis, V. verecunda and V. acuminata, in combination with reported precursor sequences. The distribution of the cyclotide precursors in the genus Viola was analyzed in relation to the infrageneric phylogeny, providing insights into the overall distribution of cyclotides within the genus. The structures and activities of predicted cyclotides are linked to the evolution of their precursors and the associated selective pressures. Furthermore, sequence variations between related precursors were generalized to deduce evolutionary trends, and to shed light on the evolution into novel mature cyclotides with the emergence of new functions.
IdentifiersURN: urn:nbn:se:uu:diva-292958OAI: oai:DiVA.org:uu-292958DiVA: diva2:927084