The Hippo pathway uses different machinery to control cell fate and organ size
Jonathan M. Pojer,
Samuel A. Manning,
Benjamin Kroeger,
Shu Kondo,
Kieran F. Harvey
Affiliations
Jonathan M. Pojer
Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia
Samuel A. Manning
Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
Benjamin Kroeger
Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
Shu Kondo
Laboratory of Invertebrate Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, Japan
Kieran F. Harvey
Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia; Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia; Corresponding author
Summary: The Hippo pathway is a conserved signaling network that regulates organ growth and cell fate. One such cell fate decision is that of R8 photoreceptor cells in the Drosophila eye, where Hippo specifies whether cells sense blue or green light. We show that only a subset of proteins that control organ growth via the Hippo pathway also regulate R8 cell fate choice, including the STRIPAK complex, Tao, Pez, and 14-3-3 proteins. Furthermore, key Hippo pathway proteins were primarily cytoplasmic in R8 cells rather than localized to specific membrane domains, as in cells of growing epithelial organs. Additionally, Warts was the only Hippo pathway protein to be differentially expressed between R8 subtypes, while central Hippo pathway proteins were expressed at dramatically lower levels in adult and pupal eyes than in growing larval eyes. Therefore, we reveal several important differences in Hippo signaling in the contexts of organ growth and cell fate.
