ZFIN ID: ZDB-PUB-120410-13
Distinct and separable activities of the endocytic clathrin-coat components Fcho1/2 and AP-2 in developmental patterning
Umasankar, P.K., Sanker, S., Thieman, J.R., Chakraborty, S., Wendland, B., Tsang, M., and Traub, L.M.
Date: 2012
Source: Nature cell biology   14(5): 488-501 (Journal)
Registered Authors: Tsang, Michael
Keywords: none
MeSH Terms:
  • Adaptor Protein Complex 2/genetics
  • Adaptor Protein Complex 2/physiology*
  • Body Patterning*
  • Clathrin/metabolism*
  • Embryonic Development
  • Endocytosis*
  • Gene Silencing
  • HeLa Cells
  • Humans
  • Membrane Proteins
  • Proteins/genetics
  • Proteins/physiology*
PubMed: 22484487 Full text @ Nat. Cell Biol.

Clathrin-mediated endocytosis occurs at multiple independent import sites on the plasma membrane, but how these positions are selected and how different cargo is simultaneously recognized is obscure. FCHO1 and FCHO2 are early-arriving proteins at surface clathrin assemblies and are speculated to act as compulsory coat nucleators, preceding the core clathrin adaptor AP-2. Here, we show that the μ-homology domain of FCHO1/2 represents an endocytic interaction hub. Translational silencing of fcho1 in zebrafish embryos causes strong dorsoventral patterning defects analogous to Bmp signal failure. The Fcho1 μ-homology domain interacts with the Bmp receptor Alk8, uncovering an endocytic component that positively modulates Bmp signal transmission. Still, the fcho1 morphant phenotype is distinct from severe embryonic defects apparent when AP-2 is depleted. Our data thus challenge the primacy of FCHO1/2 in coat initiation.