Alan Hall
In 1982, Hall helped identify transforming sequences in human sarcoma cells lines at the Institute for Cancer Research in London.
[7] Alan Hall showed the specificity of Rho in the stimulation of focal adhesions and stress fibres formation in fibroblasts in the presence of extracellular factors in 1992.
He first realised that the addition of bovine fetal calf serum (FCS) to Swiss 3T3 cells increased the polymerisation of actin and assembly of stress fibres.
The immunofluorescence following the increase of vinculin and talin, two cytoskeletal proteins, at the intracellular face of the plasma membrane with Val14rhoA microinjection showed the association of focal adhesions with the end of the new stress fibres.
Immunofluorescence and antibody techniques were used to localise the mutant V12rac1 protein after being microinjected into the cytoplasm of confluent serum-starved Swiss 3T3 cells.
It was known at this point that several identified Rho targets were structurally similar to scaffold proteins, which have been shown in the past to mediate interaction specificity in other pathways.
Further evidence of the importance of Ral was provided when cortical neurons were depleted of endogenous RalA and RalB isoforms by RNA interference (RNAi) and showed a decrease in the branching.
By plating SCG on plastic dishes in presence of different substrates, Hall realised that Ral was activated by laminin to induce this branching.
Finally, Ral mutants unable to bind to their specific effector proteins showed that RalA and RalB isoforms promote branching through exocyst complex and phospholipase D respectively.
[12] In 2010, Hall analysed a number of Rho signalling pathways, which regulate the formation of apical junctions in human bronchial epithelial (HBE) cells.
Downregulation of RhoA in the HBE cell lines using siRNAs showed a lack of apical junction formation in contrast with the controls.
In 1993, Alan Hall was awarded the Feldberg Foundation Prize for his work on the role GTP-binding proteins played on signal transduction pathways.
