Figure 4.

The MBR of Smy1p is necessary to overcome the temperature-sensitive growth defect of the myo2–66 mutant. (A) The yeast strain SLY88 carrying the myo2–66 mutation was transformed with high-copy-number plasmid vectors YEp352 (a), YEpSMY1₆₄₇ (b), YEpSMY1₅₇₈ (missing the MBR) (c), and YEpSMY1–26 (full length) (d) . Transformants were grown at permissive temperature (24°C) and at restrictive temperature (33°C) for 3–4 d on selective medium. The myo2–66 mutant cells overexpressing full-length Smy1p (656 amino acids) (d) and Smy1p truncated at amino acid 647 (b) were able to grow at 33°C, but those without overexpressed Smy1p (a) or with Smy1p truncated at amino acid 578 (c) were not. (B) Western analysis of vector YEp352, YEpSMY1₅₇₈ (missing the MBR), YEpSMY1₆₄₇, and YEpSMY1 (full length) in the smy1Δ (null) strain SLY86 demonstrates nearly equivalent levels of protein expression. Constructs are described in MATERIALS AND METHODS.