Regulation of Nuclear Translocation of the Myb1 Transcription Factor by TvCyclophilin 1 in the Protozoan Parasite Trichomonas vaginalis

Abstract

Background: Myb1 mediates transcription suppression of an ap65-1 gene. Results: TvCyP1 may accelerate conformational changes in Myb1 to enable its release from certain vesicles. Conclusion: TvCyP1 is essential for moving Myb1 toward the nucleus. Significance: This study elucidates a key step in nuclear translocation of Myb1 and provides tools to study the physiological role of TvCyP1.

Membrane localization of a Myb3 transcription factor regulated by a TvCyP1 cyclophilin in the parasitic protozoan Trichomonas vaginalis

“…In fractions separated from P15 (Fig. B, right panel), Myb3 was detected in fractions 1 and 2, previously referred to as V Myb , along with Myb1 and Tv CyP1 . Intriguingly, Myb3, but not Myb1, was also detected in hydrogenosomal fractions 5–7 along with Tv CyP1 and pyruvate ferrodoxin oxidoreductase .…”

“…Since conformational switch of the Gly‐Pro bond in Myb1 is crucial for its subcellular distribution and nuclear translocation , the Gly‐Pro bonds in Myb3 may exert similar effects on Myb3. To test this possibility, a transgenic system overexpressing HA‐Myb3 in T. vaginalis was used to study potential roles of Tv CyP1‐binding motifs in Myb3.…”

“…D). Unlike the binding of Tv CyP1 to Myb1 , the binding of Tv CyP1 to Myb3 was slightly reduced with the abortion of its enzyme activity (Fig. ), implying that Tv CyP1 may have an additional binding motif other than the enzyme pocket that displays differential binding activities for Myb1 and Myb3.…”

“…Unfortunately, stable transgenic expression of Myb1 failed in numerous attempts, hence further study on this phenomenon remains difficult. Tv CyP1 was also shown to regulate the level of Myb3 on V Myb , indicating that Myb3 is a likely substrate for Tv CyP1.…”

Signal Transduction Triggered by Iron to Induce the Nuclear Importation of a Myb3 Transcription Factor in the Parasitic Protozoan Trichomonas vaginalis

“…Reaction conditions for antibodies from commercial sources, including mouse anti-␣-tubulin (5000ϫ) (DM1A; Sigma), rat anti-HA (2000ϫ) (3F10; Roche Applied Science), rabbit anti-acetylhistone H3K9 (3000ϫ; Upstate Biotechnology, Inc.), rabbit anti-ubiquitin (1000ϫ; Santa Cruz Biotechnology, Inc.), rabbit anti-phospho-(Ser/Thr)PKA substrate (1000ϫ; Cell Signaling), rabbit anti-PKA␥ (catalytic subunit) (phospho-Thr 197 ) (3000ϫ; Abcam), mouse anti-phospho-Thr/ Pro 101 (2000ϫ; Cell Signaling), and anti-His 6 (5000ϫ; Clontech) were performed as described by suppliers. Myb1, Myb2, Myb3, TvCyP1, TvHsp70-1, and TvPKAc were detected by mouse anti-Myb1 (1000ϫ) (24), rabbit anti-Myb2 (2000ϫ) (25), rabbit anti-Myb3 (2000ϫ) (26), rat anti-TvCyP1 (3000ϫ) (27), rat anti-TvHsp70-1 (5000ϫ) (36), and rat anti-TvPKAc (1000ϫ), respectively.…”