Interaction in vitro; bait produced and labeled by in vitro transcription; prey derived from wild-type embryo extract.

Biotin labeled RNA was pulled down using streptavidin beads.

Interaction in vitro; bait produced and labeled by in vitro transcription; prey produced by in vitro translation.

Biotin labeled RNA was pulled down using streptavidin beads.

Authors used the long isoform of how in these experiments.

Interaction in vitro; bait produced and labeled by in vitro transcription; prey produced by in vitro translation.

Interaction in vitro; bait produced and labeled by in vitro transcription; prey produced by in vitro translation.

sr isoform A corresponds to transcripts that use the upstream alternative promoter (e.g., sr-RA and sr-RD). In reporter assays, co-transfection of how(S) isoform increases the efficiency with which the isoform A-specific intron is spliced.

Biotin labeled RNA was pulled down using streptavidin beads.

Interaction in vitro; bait produced and labeled by in vitro transcription; prey produced by in vitro translation.

The HRE site is not recognized by how if present in an RNA stem, only if found in a loop (of 13nt or larger) or in unstructured RNA.

Biotin labeled RNA was pulled down using streptavidin beads.

Interaction in vitro; bait produced and labeled by in vitro transcription; prey derived from transfected S2R+ cell extract.

Binding of how to the HRE is reduced by 70% upon treatment of cells with U0126 (a MEK inhibitor), presumably by reducing how dimerization. Mutation of MAPK/ERK phosphorylation sites (T59 and T64 to Alanine) did not disrupt binding, presumably because mutant transfected proteins could dimerize with endogenous (phosphorylated) how.

Biotin labeled RNA was pulled down using streptavidin beads.