Quantification of a Non-conventional Protein Secretion: The Low-Molecular-Weight FGF-2 Example.
Quantification of secreted factors is most often measured with enzyme-linked immunosorbent assay (ELISA), Western Blot, or more recently with antibody arrays. However, some of these, like low-molecular-weight fibroblast growth factor-2 (LMW FGF-2; the 18 kDa form), exemplify a set of secreted but almost non-diffusible molecular actors. It has been proposed that phosphorylated FGF-2 is secreted via a non-vesicular mechanism and that heparan sulfate proteoglycans function as extracellular reservoir but also as actors for its secretion. Heparan sulfate is a linear sulfated polysaccharide present on proteoglycans found in the extracellular matrix or anchored in the plasma membrane (syndecan). Moreover the LMW FGF-2 secretion appears to be activated upon FGF-1 treatment. In order to estimate quantification of such factor export across the plasma membrane, technical approaches are presented (evaluation of LMW FGF-2: (1) secretion, (2) extracellular matrix reservoir, and (3) secretion modulation by surrounding factors) and the importance of such procedures in the comprehension of the biology of these growth factors is underlined.
Centre de Recherches en Cancérologie de Toulouse - CRCT UMR1037 Inserm/Université Toulouse III Paul Sabatier ERL5294 CNRS, Oncopole de Toulouse 2 Avenue, Hubert Curien, CS 53717, 31037, Toulouse Cedex 1, France.
Tania
T
Arcondéguy
Centre de Recherches en Cancérologie de Toulouse - CRCT UMR1037 Inserm/Université Toulouse III Paul Sabatier ERL5294 CNRS, Oncopole de Toulouse 2 Avenue, Hubert Curien, CS 53717, 31037, Toulouse Cedex 1, France.
Christian
C
Touriol
Centre de Recherches en Cancérologie de Toulouse - CRCT UMR1037 Inserm/Université Toulouse III Paul Sabatier ERL5294 CNRS, Oncopole de Toulouse 2 Avenue, Hubert Curien, CS 53717, 31037, Toulouse Cedex 1, France. eric.lacazette@inserm.fr.
Eric
E
Lacazette
D002704:Chlorates / Q000494:pharmacology; D016220:Fibroblast Growth Factor 1 / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008970:Molecular Weight; D011133:Polysaccharide-Lyases; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D055571:Secretory Pathway / Q000187:drug effects
D002704:Chlorates; D011506:Proteins; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; D011133:Polysaccharide-Lyases; C114663:heparinase II; C032706:sodium chlorate
FGF-1 stimulation; Heparinase II; LMW FGF-2 secretion; NaClO3