Multiple regulatory inputs converge on cortactin to control invadopodia biogenesis and extracellular matrix degradation.
Invadopodia are proteolytically active protrusions formed by invasive tumoral cells when grown on an extracellular matrix (ECM) substratum. Although many molecular components have been defined, less is known of the formation and regulation of invadopodia. The multidomain protein cortactin, which is involved in the regulation of actin polymerisation, is one such component, but how cortactin is modulated to control the formation of invadopodia has not been elucidated. Here, a new invadopodia synchronization protocol is used to show that the cortactin N-terminal acidic and SH3 domains, involved in Arp2/3 complex and N-WASP binding and activation, respectively, are both required for invadopodia biogenesis. In addition, through a combination of RNA interference and a wide array of cortactin phosphorylation mutants, we were able to show that three convergent regulatory inputs based on the regulation of cortactin phosphorylation by Src-family kinases, Erk1/Erk2 and PAK are necessary for invadopodia formation and extracellular matrix degradation. These findings suggest that cortactin is a scaffold protein bringing together the different components necessary for the formation of the invadopodia, and that a fine balance between different phosphorylation events induces subtle changes in structure to calibrate cortactin function.
Ayala
Inmaculada
I
Tumour Cell Invasion Laboratory, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, S. Maria Imbaro (Chieti), Italy.
Baldassarre
Massimiliano
M
Giacchetti
Giada
G
Caldieri
Giusi
G
Tetè
Stefano
S
Luini
Alberto
A
Buccione
Roberto
R
D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D022081:Cell Surface Extensions / Q000473:pathology / Q000502:physiology*; D051356:Cortactin / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D005109:Extracellular Matrix / Q000502:physiology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D008545:Melanoma / Q000473:pathology / Q000503:physiopathology; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D051381:Rats; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000378:metabolism; D054462:p21-Activated Kinases / Q000378:metabolism; D018909:src Homology Domains; D019061:src-Family Kinases / Q000378:metabolism
D051376:Actin-Related Protein 2-3 Complex; D051356:Cortactin; C495870:Cttn protein, rat; D017931:DNA Primers; D011994:Recombinant Proteins; C495771:WASL protein, human; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D019061:src-Family Kinases; D054462:p21-Activated Kinases; D048049:Extracellular Signal-Regulated MAP Kinases