Mass spectroscopic phosphoprotein mapping of Ral binding protein 1 (RalBP1/Rip1/RLIP76)
- Department of Molecular Physiology and Biological Physics, University of Virginia Health Sciences Center, Charlottesville, VA 22908 (United States)
RalBP1, a multifunctional protein implicated in cancer cell proliferation, radiation and chemoresistance, and ligand dependent receptor internalization, is upregulated in bladder cancer and is a downstream effector of RalB, a GTPase associated with metastasis. RalBP1 can be regulated by phosphorylation by protein kinase C (PKC). No studies have comprehensively mapped RalBP1 phosphorylation sites or whether RalB affects these. We identified 14 phosphorylation sites of RalBP1 in human bladder carcinoma UMUC-3 and embryonic kidney derived 293T cells. The phosphorylated residues are concentrated at the N-terminus. Ten of the first 100 amino acids of the primary structure were phosphorylated. Nine were serine residues, and one a threonine. We evaluated the effect of RalB overexpression on RalBP1 phosphorylation and found the largest change in phosphorylation status at S463 and S645. Further characterization of these sites will provide novel insights on RalBP1 biology, its functional relationship to RalB and possible avenues for therapeutic intervention.
- OSTI ID:
- 21032920
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 362, Issue 1; Other Information: DOI: 10.1016/j.bbrc.2007.07.163; PII: S0006-291X(07)01631-2; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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