Figure 4. Different homologs complement the phenotypes of the Sec61β knockout in fission and budding yeast.

(A) Cold sensitivity of S. pombe Δsbh1 cells is rescued by different Sec61β homologs. S. pombe Δsbh1 cells (SP15039) expressing different Sec61β homologs from S. pombe (SP), S. cerevisiae (SC) or human (HS) were serially-diluted (10⁻¹–10⁻⁴) and spotted on MM+AL plates. Growth was monitored during 7 days at the indicated temperatures. SP_Sec61γ was used as a negative control. Results are representative of three or more independent experiments. (B) Heat sensitivity of S. cerevisiae sbh1Δsbh2Δ cells is rescued by different Sec61β homologs. S. cerevisiae sbh1Δsbh2Δ cells (SC3232) expressing Sec61β homologs from S. pombe (SP), S. cerevisiae (SC) or human (HS) were serially-diluted (10⁻¹–10⁻⁴) and spotted on SD-L plates. Growth was monitored during 5 days at the indicated temperatures. SC_Sec61γ was used as a negative control. Results are representative of three or more independent experiments. (C) Suppression of S. pombe Δsbh1 SDS sensitivity by different Sec61β homologs. SDS-sensitivity halo was measured after 3–5 days of incubation at the indicated temperatures for cultures of the strains presented in (A). Data shown are mean±standard deviation of three or more independent experiments. *** indicates p<0.001 for Student's t-test versus WT.