A PP2A regulatory subunit positively regulates Ras-mediated signaling during Caenorhabditis elegans vulval induction (original) (raw)

1. Derek S. Sieburth,
2. Meera Sundaram,
3. Robyn M. Howard, and
4. Min Han
5. Howard Hughes Medical Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado 80309-0347 USA; Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6145 USA

Abstract

We describe evidence that a regulatory B subunit of protein phosphatase 2A (PP2A) positively regulates an RTK–Ras–MAP kinase signaling cascade during Caenorhabditis elegans vulval induction. Although reduction of sur-6 PP2A-B function causes few vulval induction defects in an otherwise wild-type background,sur-6 PP2A-B mutations suppress the Multivulva phenotype of an activated ras mutation and enhance the Vulvaless phenotype of mutations in lin-45 raf, sur-8, or mpk-1. Double mutant analysis suggests that sur-6 PP2A-B acts downstream or in parallel to ras, but likely upstream of_raf_, and functions with ksr-1 in a common pathway to positively regulate Ras signaling.

• Suppressor of ras
• phosphatase 2A
• vulval induction
• KSR
• Raf
• SUR-8

Footnotes

• ↵Corresponding author.

• E-MAIL mhan{at}colorado.edu; FAX (303) 492-7744.

• • Received June 24, 1999.
  • Accepted August 11, 1999.

• Cold Spring Harbor Laboratory Press

•