α-Actinin TvACTN3 of Trichomonas vaginalis Is an RNA-Binding Protein That Could Participate in Its Posttranscriptional Iron Regulatory Mechanism
Figure 1
Presence of RNA-binding proteins in iron-depleted T. vaginalis. (a) RNA gel-shift assays (REMSA) to detect RNA-protein complex (RPC) formation using IRE-fer (lanes 1–3) and IRE-tvcp4 (lanes 4–6) RNA probes and T. vaginalis cytoplasmic extracts from parasites grown in iron-rich (H) (lanes 2 and 3) or iron-depleted (L) (lanes 5 and 6) medium. Experiments with IRE-fer are controls. RNA free probes used as negative controls (lanes 1 and 4). (b) REMSA competition assays performed with the IRE-fer and IRE-tvcp4 RNA probes and T. vaginalis cytoplasmic extracts in the absence of competitors (lanes 2 and 10) or in the presence of a 50- or 100-fold molar excess of unlabeled IRE-fer RNA (lanes 3 and 4), IRE-tvcp4 (lanes 13 and 14), or unrelated transcript (lanes 7, 8 and 15, 16). A cross-competition assay in the presence of a 50- or 100-fold molar excess of unlabeled IRE-tvcp4 RNA (lanes 5 and 6) and IRE-fer RNA (lanes 11 and 12). Experiments were performed three times and yielded similar results.
