title: Calponin-like Chd64 is partly disordered.
abstract: 20-hydroxyecdysone (20E) and juvenile hormone (JH) signaling pathways interact to regulate insect development. Recently, two proteins, a calponin-like Chd64 and immunophilin FKBP39 have been found to play a pivotal role in the cross-talk between 20E and JH, although the molecular basis of interaction remains unknown. The aim of this work was to identify the structural features that would provide understanding of the role of Chd64 in multiple and dynamic complex that cross-links the signaling pathways. Here, we demonstrate the results of in silico and in vitro analyses of the structural organization of Chd64 from Drosophila melanogaster and its homologue from Tribolium castaneum. Computational analysis predicted the existence of disordered regions on the termini of both proteins, while the central region appeared to be globular, probably corresponding to the calponin homology (CH) domain. In vitro analyses of the hydrodynamic properties of the proteins from analytical size-exclusion chromatography and analytical ultracentrifugation revealed that DmChd64 and TcChd64 had an asymmetrical, elongated shape, which was further confirmed by small angle X-ray scattering (SAXS). The Kratky plot indicated disorderness in both Chd64 proteins, which could possibly be on the protein termini and which would give rise to specific hydrodynamic properties. Disordered tails are often involved in diverse interactions. Therefore, it is highly possible that there are intrinsically disordered regions (IDRs) on both termini of the Chd64 proteins that serve as platforms for multiple interaction with various partners and constitute the foundation for their regulatory function.
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kozłowska
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Aneta
authors.initials: A
authors.lastname: Tarczewska
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Jakób
authors.affiliation: Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland.
authors.forename: Kamil
authors.initials: K
authors.lastname: Szpotkowski
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Wojtas
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Rymarczyk
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ożyhar
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D002942:Circular Dichroism; D004268:DNA-Binding Proteins / Q000737:chemistry*; D029721:Drosophila Proteins / Q000737:chemistry*; D004331:Drosophila melanogaster / Q000737:chemistry; D004441:Ecdysterone / Q000737:chemistry* / Q000378:metabolism; D007605:Juvenile Hormones / Q000737:chemistry* / Q000378:metabolism; D008840:Microfilament Proteins / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D053838:Scattering, Small Angle; D020539:Sequence Analysis, Protein; D014231:Tribolium / Q000737:chemistry; D014961:X-Ray Diffraction; D000096985:Calponins
chemical_list: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D004441:Ecdysterone; D007605:Juvenile Hormones; D008840:Microfilament Proteins; D000096985:Calponins; C000598594:Chd64 protein, Drosophila