Collection of insulin, EGF and α2-Macroglobulin in the same patches on the surface of cultured fibroblasts and common internalization Academic Article uri icon


MeSH Major

  • Fractures, Compression
  • Lumbar Vertebrae
  • Spinal Fractures
  • Thoracic Vertebrae


  • We have used video intensification microscopy to observe fluorescent derivatives of insulin, epidermal growth factor and alpha2-macroglobulin added to Swiss 3T3-4 cells. At 4 degrees C, each of these polypeptides binds diffusely to specific receptors on the cell surface. When the cells are warmed to 23 or 37 degrees C, the bound insulin epidermal growth factor or alpha2-macroglobulin rapidly forms patches on the cell surface and is internalized. Using fluorescein-labeled alpha2-macroglobulin and rhodamine-labeled derivatives of insulin and epidermal growth factor, we show that all three polypeptides are internalized within the same vesicles by a common pathway. The mechanism for the internalization of these molecules is discussed.

publication date

  • January 1978



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1016/0092-8674(78)90336-7

Additional Document Info

start page

  • 805

end page

  • 10


  • 14


  • 4