Fig. 1

Syncrip interacts with mRNA targets using multiple RNA-binding domains. a Schematic of the domain organisation and sequence conservation of Syncrip protein from Drosophila and human. The domains are drawn as coloured rectangles and the sequence identity between Drosophila and human individual domains is shown below each equivalent pair. b Workflow of the RBDmap assay. c Mapping of the RNA-binding sites detected in human Syncrip by RBDmap. Top: x-axis represents Syncrip from N- to C-terminus. y-axis represent the fold change between the RNA-bound (i.e., peptides crosslinked to RNA) and released (i.e., peptides released to the supernatant after protease treatment) fractions. RNA-bound peptides identified with FDR < 0.01 are depicted as red lines. Candidate RNA-bound peptides (FDR < 0.1) are depicted in salmon. Peptides released to the supernatant after proteolytic treatment are depicted in cyan. Middle: sequence propensity to bind RNA based on the superset of RNA-bound peptides of human RBPs identified by RBDmap. This prediction was performed by shrinkage discriminant analysis employing a binary classifier, which consists of the sequences of the RNA-bound peptides (positive examples) and that of the peptides lacking RNA-binding activity (negative examples). Resulting algorithm was applied to identify the regions of Syncrip with high probability to interact with RNA. Bottom: lines indicate the different domains of Syncrip, as a reference. The colour of the line(s) corresponds to the colour of the domains in panel a. In addition, the conserved RNA-binding sequence N-terminal to the canonical RRM1 fold domain is indicated by a yellow line. d Sequence alignment of the N-terminal region of Syncrip. The coloured lines below the sequences define the boundaries of the domains as reported in a and c