High impact information on Fgd4

• Two actions of frabin: direct activation of Cdc42 and indirect activation of Rac [1].
• We have found here that frabin induces the formation of not only filopodium-like microspikes but also lamellipodium-like structures in NIH3T3 and L fibroblasts [1].
• Frabin has one actin filament-binding (FAB) domain, one Dbl homology (DH) domain, first pleckstrin homology (PH) domain adjacent to the DH domain, one cysteine-rich FYVE domain, and second PH domain from the N-terminus to the C-terminus in this order [1].
• RESULTS: Various truncated mutants of frabin were co-expressed with a dominant active mutant (DA) of Cdc42, Rac1DA, or full-length frabin in L fibroblasts [2].
• CONCLUSION: These results suggest that frabin recognizes a specific actin structure(s) through FAB and a specific membrane structure(s) through FAB and the region containing DH, PH1, FYVE and PH2 [2].

Biological context of Fgd4

• Identification of splicing variants of Frabin with partly different functions and tissue distribution [3].

Anatomical context of Fgd4

• In MDCK epithelial cells, frabin-alpha formed microspikes but frabin-beta or -gamma did not [3].
• As to lamellipodia, frabin-alpha formed them; frabin-beta formed them to a small extent; and frabin-gamma did not [3].

Other interactions of Fgd4

• It is likely that frabin associates with the specific actin and membrane structures and activates Cdc42 and Rac in the vicinity of these structures, eventually leading to morphological changes [2].
• Previous work shows that FGD1 is the founding member of a family of related genes including the mouse Fgd2 gene and the rat Frabin gene [4].

References