The World of Functional Amyloid - The Functional Fold: Amyloid Structures in Nature - page 11

role in many biological processes. Known examples of amyloid
function range from protecting organisms from the environment
and fulfilling structural roles to influencing chemical reactions
within the cell. The discovery of functional amyloid challenges the
long held belief that amyloid represents an inherently toxic structure
associated only with aberrant misfolding and misassembly. Like any
other protein structure, amyloid can be useful for function or can
contribute to disease, particularly when its formation is unregulated.
Further study and better methods of intracellular amyloid detection
will likely reveal many more examples of functional amyloid.
Understanding how amyloid structure, function, and regulation are
related will have consequences for both treating amyloid-

related diseases as well as for the use of amyloid as a biomaterial for
related applications.

in vivo

Acknowledgements

This work was supported by the National Institutes of Health
(DK46335, NS50636 to J.W.K., and AG18917 to J.W.K. and William
E. Balch), the Skaggs Institute of Chemical Biology and the Lita
Annenberg Hazen Foundation. We acknowledge the contributions
of our longtime collaborator William E. Balch for refining our ideas
about functional amyloid. Evan Powers and Colleen Fearns provided
assistance preparing this text.

References

1. Anfinsen, C. B. (1973) Science , 181 (4096), 223.

2. Daune, M. (1993) Molecular Biophysics , Oxford University Press, Oxford.

3. Chiti, F., and Dobson, C. M. (2006) Annu. Rev. Biochem. , 75 , 333.

4. Stromer, T., and Serpell, L. C. (2005) (3-4), 210.

5. Luhrs, T., Ritter, C., Adrian, M., Riek-Loher, D., Bohrmann, B., Dobeli,
H., Schubert, D., and Riek, R. (2005)

Microsc. Res. Tech. , 67

Proc. Natl. Acad. Sci. U.S.A. ,

(48), 17342.
6. Petkova, A. T., Ishii, Y., Balbach, J. J., Antzutkin, O. N., Lesapman,
R. D., Delaglio, F., and Tycko, R. (2002)

102

Proc. Natl. Acad. Sci. U.S.A. ,

(26), 16742.
7. Iwata, K., Fujiwara, T., Matsuki, Y., Akutsu, H., Takahashi, S., Naiki, H.,
and Goto, Y. (2006)

99

Proc. Natl. Acad. Sci. U.S.A., 103 (48), 18119.