Fig. 1: IHO1 C-terminus mediates IHO1-HORMAD1 interaction.
From: Seeding the meiotic DNA break machinery and initiating recombination on chromosome axes
A, B Y2H assays between IHO1 interactors (this study and22,24,113) and wild-type (1-574) or modified versions of IHO1. A Schematics show conserved domains14 and positions of phospho-serines (S) or -threonine (T) or their substitution with alanine (A) in IHO1. B Budding yeast cultures co-transformed with indicated pairs of Y2H baits (top) and preys (left side) are shown after 3 (two left images) or 2 (two right images) days of growth on drop-out plates. X marks bait-prey combinations that were omitted from Y2H due to lack of relevance. C, G Immunostaining in nuclear spread spermatocytes of 13 days postpartum (dpp) (C) and adult (G) mice. Chromosome axis (SYCP3, C overlay, G), HORMAD1 (C, G) and either ectopically expressed GFP-IHO1 (C) or endogenous IHO1 (G) were detected. Bars, 10 µm. D Quantification of localization of GFP-tagged IHO1 versions in late zygotene. IHO1 versions: wild type (WT), a mutant missing the last 7 amino acids (C7Δ) and versions where single-letter amino acid code indicates point mutations in positions 569 and 570. Block bars are means. Likelihood-ratio test, ns=P > 0.05, ***=P < 0.001, ****=P < 0.0001. Exact P values: WT vs. C7Δ and AA vs. SA P < 2.2e-16, C7Δ vs. AA P = 0,06547, SA vs. SD P = 9.445e-10, SA vs. SE P = 2.225e-06, AA vs. AS P = 3.217e-09, AS vs. DS P = 4.979e-14, AS vs. ES P = 2.966e-11, AA vs. DD P = 2.599e-09, AA vs. EE P = 0.001003. E Immunoprecipitation (IP) immunoblots from testis extracts of 13 dpp mice. Asterisk and triangles mark unspecific protein band in REC114 blot and isoforms of SYCP3, respectively. Distinct proteins were detected on separate blots. F Schematics summarizing conclusions of panel E. See also related Supplementary Fig. 2, Supplementary Table 1 and 2. Source data are provided as a Source Data file.
