Clb2 HP region residues N and K mediate regulation by Swe1. Each strain expresses the indicated CLB5 or CLB2 allele from the endogenous CLB5 promoter and lacks CLB6. Strains DGy221 (CLB5), FHy116 (CLB2), FHy285 (CLB2-E), FHy284 (CLB2-A), FHy363 (CLB2-M), FHy302 (CLB2-ME), FHy364 (CLB2-MA), FHy134 (CLB2 swe1Δ), FHy303 (CLB2-ME swe1Δ), and FHy366 (CLB2-MA swe1Δ) were synchronized in G1 with α-factor and released at 23°. Samples were collected every 12 min for DNA content analysis (A) and budding analysis (B).