Article synthesizing and testing the synthetic peptide AKRRRLSSLRASTSKSESSQK (56-21) which corresponds to the carboxyl-terminal 21 amino acids of human ribosomal protein S6 as a substrate for S6/H4 kinase purified from human placenta. The data suggests that multiple S6 kinases may be required to phosphorylate S6 at all five sites which are modified in vivo.
January 5, 1991
Brandon, Stanley D. & Masaracchia, Ruthann A.
Article proposing a model in which phosphorylation of sites 1 and 2 occurs sequentially. The model proposes that trypsin treatment of the inactive holoenzyme removes an inhibitory rac-binding domain which blocks MgATP access to the catalytic site. The pseudosubstrate domain at site 1 is autophosphorylated and subsequent bimolecular autophosphorylation at site 2 fully opens the catalytic site.
September 8, 1995
Benner, Gretchen E.; Dennis, Patrick B. & Masaracchia, Ruthann A.
Article describing a novel S6 kinase isolated from human placenta which autoactivates through autophosphorylation in vitro. The data supports the hypothesis that this previously uncharacterized S6 kinase belongs to a unique family of protein kinases which utilize autophosphorylation as part of their in vivo activation mechanism.
September 15, 1993
Dennis, Patrick B. & Masaracchia, Ruthann A.