The annexins are a group of homologous, calcium-dependent, membrane- binding proteins present in a wide variety of cells and tissues. Although normally soluble, in the presence of calcium these proteins bind to acidic lipids in membranes leading to lipid immobilization and sequestration. Most members of the family will also promote the calcium-dependent aggregation and fusion of either pure lipid vesicles or biological membranes. The annexins may underlie a number of different biological processes both inside and outside of cells, including membrane fusion during exocytosis, interactions between the cytoskeleton and membranes, regulation of lipid organization and metabolism, ion fluxes across membranes, and regulation of blood coagulation. The goals of this study are to determine the structural features of the annexins that underlie their interactions with membranes, and to use this information to design inhibitors of the activities of these proteins that may be applied to cells to determine the functions of the annexins in vivo. The structures of several annexins will be determined by X-ray diffraction analysis. The structural data will be used to design mutations in the annexins that should reveal the relationship between specific structural features of these proteins and certain in vitro activities. Specific annexin inhibitors will be designed, beginning with synthetic peptides corresponding to the N-terminal regions of the proteins that are critical for control of their membrane-aggregating activity. Effective in vitro inhibitors will be introduced into model secretory cells and fibroblasts to determine their effects on exocytosis and endocytosis, cell morphology and motility, and membrane-cytoskeletal organization. The information gained about the structure, mechanism of action, and modes of inhibition of these proteins may permit the development of pharmacological means to regulate the annexins in disorders of hormone release, blood coagulation, or cell structure.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM053266-01
Application #
2192606
Study Section
Biophysical Chemistry Study Section (BBCB)
Program Officer
Abraham, Kristin M
Project Start
1995-07-01
Project End
1999-06-30
Budget Start
1995-07-01
Budget End
1996-06-30
Support Year
1
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of Virginia
Department
Pharmacology
Type
Schools of Medicine
DUNS #
001910777
City
Charlottesville
State
VA
Country
United States
Zip Code
22904
Creutz, C E; Snyder, S L; Schulz, T A (2004) Characterization of the yeast tricalbins: membrane-bound multi-C2-domain proteins that form complexes involved in membrane trafficking. Cell Mol Life Sci 61:1208-20
Sohma, H; Creutz, C E; Gasa, S et al. (2001) Differential lipid specificities of the repeated domains of annexin IV. Biochim Biophys Acta 1546:205-15
Daigle, S N; Creutz, C E (1999) Transcription, biochemistry and localization of nematode annexins. J Cell Sci 112 ( Pt 12):1901-13
Sohma, H; Creutz, C E; Saitoh, M et al. (1999) Characterization of the Ca2+-dependent binding of annexin IV to surfactant protein A. Biochem J 341 ( Pt 1):203-9