Files in this Data Supplement:

• Supplemental file 1 - Fig. S1 (MG132 does not increase ROS).
  Zipped TIF file, 15K.
• Supplemental file 2 - Fig. S2 (Ubiquitination of GST-SMN and GST-SMNΔ7).
  Zipped TIF file, 43K.
• Supplemental file 3 - Fig. S3 (Cysteine/methionine starvation shifts Gemins sedimentation patterns).
  Zipped TIF file, 158K.
• Supplemental file 4 - Legends to Fig. S1 to S3.
  Zipped MS Word document, 5K.