A novel molecular mechanism of autophosphorylation-dependent activation of the ser/thr S6/H4 kinase isolated from human placenta is described. Phosphopeptide mapping of the enzyme was used to determine the rate and extent of site-specific autophosphorylation. These data were correlated to phosphotransferase activity of the protein kinase. The results indicated that a sequential phosphorylation of two sites in the catalytic domain is required for maximum activation. Kinetic analysis determined that site 1 is modified by an intramolecular phosphorylation, and site 2 is modified by an intermolecular phosphorylation. On the basis of these data a model is proposed in which autophosphorylation of the pseudosubstrate domain and on a serine residue in subdomain VIII are both required for maximum activation of the S6/H4 kinase.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc332785 |
| Date | 12 1900 |
| Creators | Benner, Gretchen E. (Gretchen Evonne) |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | vii, 76 leaves : ill., Text |
| Rights | Public, Benner, Gretchen E. (Gretchen Evonne), Copyright, Copyright is held by the author, unless otherwise noted. All rights reserved. |
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