| 2007 JASN IMPACT FACTOR 7.111 | HOME AUTHOR INFO EDITORIAL BOARD SUBSCRIBE FEEDBACK ALERTS HELP | |||
| CURRENT ISSUE | ARCHIVES | JASN Express | ONLINE SUBMISSION | |


*
Department of Cellular and Molecular Medicine, University of California
San Diego, La Jolla, California.
Department of Pathology, University of California San Diego, La Jolla,
California.
Correspondence to Dr. Marilyn Gist Farquhar, Department of Cellular and Molecular Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0651. Phone: 858-534-7711; Fax: 858-534-8549; E-mail: mfarquhar{at}ucsd.edu
Abstract. Ankyrin-repeat family A protein (ANKRA) is a novel protein that interacts directly and specifically with the cytoplasmic tail of megalin in the yeast two-hybrid system and glutathione-S-transferase pull-down assays. ANKRA has three ankyrin repeats and shows 61% overall homology to regulatory factor X, ankyrin repeat-containing protein. Mapping studies show that the three ankyrin repeats and C-terminus of ANKRA are required for binding to a unique juxtamembrane, 19-amino acid sequence on the megalin tail. Point mutational analysis reveals that a proline-rich motif (PXXPXXP) within this region is the site of ANKRA binding. ANKRA interacts with megalin but not with low-density lipoprotein receptor related protein, in keeping with the fact that the sequence of the megalin tail is unique. By cell fractionation, ANKRA is found both in the cytosol and associated with membranes enriched in megalin in L2 cells and proximal tubule cells. By immunofluorescence, ANKRA is concentrated near megalin along the plasma membrane of L2 cells and in the kidney cortex is expressed in glomerular and proximal tubule epithelia which also express megalin. These observations suggest that ANKRA may play a unique role in megalin's function as a clearance receptor in the kidney and L2 cells. In addition, ANKRA may have other partners because northern blot analysis reveals that ANKRA is more broadly expressed than megalin, and by immunofluorescence ANKRA is also expressed in connecting tubule cells and principal cells of collecting ducts.
This article has been cited by other articles:
![]() |
U. Anzenberger, N. Bit-Avragim, S. Rohr, F. Rudolph, B. Dehmel, T. E. Willnow, and S. Abdelilah-Seyfried Elucidation of megalin/LRP2-dependent endocytic transport processes in the larval zebrafish pronephros J. Cell Sci., May 15, 2006; 119(10): 2127 - 2137. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. A. McKinsey, K. Kuwahara, S. Bezprozvannaya, and E. N. Olson Class II Histone Deacetylases Confer Signal Responsiveness to the Ankyrin-Repeat Proteins ANKRA2 and RFXANK Mol. Biol. Cell, January 1, 2006; 17(1): 438 - 447. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Krawczyk, K. Masternak, M. Zufferey, E. Barras, and W. Reith New Functions of the Major Histocompatibility Complex Class II-Specific Transcription Factor RFXANK Revealed by a High-Resolution Mutagenesis Study Mol. Cell. Biol., October 1, 2005; 25(19): 8607 - 8618. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Nagai, E. I. Christensen, S. M. Morris, T. E. Willnow, J. A. Cooper, and R. Nielsen Mutually dependent localization of megalin and Dab2 in the renal proximal tubule Am J Physiol Renal Physiol, September 1, 2005; 289(3): F569 - F576. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. H. Wang, S. Gregoire, E. Zika, L. Xiao, C. S. Li, H. Li, K. L. Wright, J. P. Ting, and X.-J. Yang Identification of the Ankyrin Repeat Proteins ANKRA and RFXANK as Novel Partners of Class IIa Histone Deacetylases J. Biol. Chem., August 12, 2005; 280(32): 29117 - 29127. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-H. Lim and C.-S. Park Identification and Functional Characterization of Ankyrin-Repeat Family Protein ANKRA as a Protein Interacting with BKCa Channel Mol. Biol. Cell, March 1, 2005; 16(3): 1013 - 1025. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Hama, A. Saito, T. Takeda, A. Tanuma, Y. Xie, K. Sato, J. J. Kazama, and F. Gejyo Evidence Indicating that Renal Tubular Metabolism of Leptin Is Mediated by Megalin But Not by the Leptin Receptors Endocrinology, August 1, 2004; 145(8): 3935 - 3940. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Nagai, T. Meerloo, T. Takeda, and M. G. Farquhar The Adaptor Protein ARH Escorts Megalin to and through Endosomes Mol. Biol. Cell, December 1, 2003; 14(12): 4984 - 4996. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Saito, R. Nagai, A. Tanuma, H. Hama, K. Cho, T. Takeda, Y. Yoshida, T. Toda, F. Shimizu, S. Horiuchi, et al. Role of Megalin in Endocytosis of Advanced Glycation End Products: Implications for a Novel Protein Binding to Both Megalin and Advanced Glycation End Products J. Am. Soc. Nephrol., May 1, 2003; 14(5): 1123 - 1131. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Takeda, H. Yamazaki, and M. G. Farquhar Identification of an apical sorting determinant in the cytoplasmic tail of megalin Am J Physiol Cell Physiol, May 1, 2003; 284(5): C1105 - C1113. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. McCarthy and W. S. Argraves Megalin and the neurodevelopmental biology of sonic hedgehog and retinol J. Cell Sci., March 15, 2003; 116(6): 955 - 960. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Lou, T. McQuistan, R. A. Orlando, and M. G. Farquhar GAIP, GIPC and G{alpha}i3 are Concentrated in Endocytic Compartments of Proximal Tubule Cells: Putative Role in Regulating Megalin's Function J. Am. Soc. Nephrol., April 1, 2002; 13(4): 918 - 927. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. G. W. Norden, M. Lapsley, T. Igarashi, C. L. Kelleher, P. J. Lee, T. Matsuyama, S. J. Scheinman, H. Shiraga, D. P. Sundin, R. V. Thakker, et al. Urinary Megalin Deficiency Implicates Abnormal Tubular Endocytic Function in Fanconi Syndrome J. Am. Soc. Nephrol., January 1, 2002; 13(1): 125 - 133. [Abstract] [Full Text] [PDF] |
||||
|
HOME
CURRENT ISSUE
ARCHIVES
JASN Express
ONLINE SUBMISSION
AUTHOR INFO
EDITORIAL BOARD SUBSCRIBE FEEDBACK ALERTS HELP |
Copyright © 2008 by the American Society of Nephrology. Online ISSN: 1533-3450 Print ISSN: 1046-6673