Fig. 6. Cbl-mediated 5 integrin subunit proteasome degradation induced by FGFR2 activation requires the RING and PTB domains of Cbl. FGFR2 mutant osteoblasts were transfected with the 70Z-Cbl mutant, which lacks the RING domain required for Cbl-ubiquitin interaction, with the G306E Cbl mutant that inactivates the PTB domain of Cbl G306E, or with the empty vector (pcDNA). After 24 hours, cell lysates were immunoprecipitated (IP) with 5 integrin antibody, resolved by SDS-PAGE and blotted with anti-5 integrin.