|
|
||||||||
Departments of 1 Internal Medicine, 2 Cellular and Molecular Physiology, 3 Cell Biology, and Pathology, Department of Molecular, Cellular and Developmental Biology, School of Medicine, Yale University, New Haven, Connecticut 06520-8029; and 4 Section of Cell and Developmental Biology, Division of Biology, University of California at San Diego, La Jolla, California 92093-0368
Myosin VI is a reverse-direction molecular motor implicated in membrane transport events. Because myosin VI is most highly expressed in the kidney, we investigated its renal localization by using high-resolution immunocytochemical and biochemical methods. Indirect immunofluorescence microscopy revealed myosin VI at the base of the brush border in proximal tubule cells. Horseradish peroxidase uptake studies, which labeled endosomes, and double staining for clathrin adapter protein-2 showed that myosin VI was closely associated with the intermicrovillar (IMV) coated-pit region of the brush border. Localization of myosin VI to the IMV region was confirmed at the electron microscopic level by colloidal gold labeling of ultrathin cryosections. In addition, antigen retrieval demonstrated a small but significant pool of myosin VI on the microvilli. To confirm the association of myosin VI with the IMV compartment, these membranes were separated from other membrane compartments by using 15-25% OptiPrep density gradients. Immunoblotting of the gradient fractions confirmed that myosin VI was enriched with markers for the IMV microdomain of the brush border, suggesting that myosin VI associates with proteins in this compartment. Finally, we examined the expression of myosin VI during nephron development. We found myosin VI present in a diffuse cytoplasmic pattern at stage II (S-shaped body phase) and that it was only redistributed fully to the brush border in the stage IV nephron. These studies support a model for myosin VI function in the endocytic process of the proximal tubule.
endocytosis; clathrin; tubular reabsorption
This article has been cited by other articles:
![]() |
M. E. Maurer and J. A. Cooper The adaptor protein Dab2 sorts LDL receptors into coated pits independently of AP-2 and ARH J. Cell Sci., October 15, 2006; 119(20): 4235 - 4246. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. K. K. Leong, A. Devillez, M. B. Sandberg, L. E. Yang, D. K. P. Yip, J. B. Klein, and A. A. McDonough Effects of ACE inhibition on proximal tubule sodium transport Am J Physiol Renal Physiol, April 1, 2006; 290(4): F854 - F863. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. E. Yang, A. B. Maunsbach, P. K.K. Leong, and A. A. McDonough Redistribution of Myosin VI from Top to Base of Proximal Tubule Microvilli during Acute Hypertension J. Am. Soc. Nephrol., October 1, 2005; 16(10): 2890 - 2896. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Osterweil, D. G. Wells, and M. S. Mooseker A role for myosin VI in postsynaptic structure and glutamate receptor endocytosis J. Cell Biol., January 17, 2005; 168(2): 329 - 338. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. E. Yang, A. B. Maunsbach, P. K. K. Leong, and A. A. McDonough Differential traffic of proximal tubule Na+ transporters during hypertension or PTH: NHE3 to base of microvilli vs. NaPi2 to endosomes Am J Physiol Renal Physiol, November 1, 2004; 287(5): F896 - F906. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Swiatecka-Urban, C. Boyd, B. Coutermarsh, K. H. Karlson, R. Barnaby, L. Aschenbrenner, G. M. Langford, T. Hasson, and B. A. Stanton Myosin VI Regulates Endocytosis of the Cystic Fibrosis Transmembrane Conductance Regulator J. Biol. Chem., September 3, 2004; 279(36): 38025 - 38031. [Abstract] [Full Text] [PDF] |
||||
![]() |
S A Mohiddin, Z M Ahmed, A J Griffith, D Tripodi, T B Friedman, L Fananapazir, and R J Morell Novel association of hypertrophic cardiomyopathy, sensorineural deafness, and a mutation in unconventional myosin VI (MYO6) J. Med. Genet., April 1, 2004; 41(4): 309 - 314. [Full Text] [PDF] |
||||
![]() |
J. B. Wade, J. Liu, R. A. Coleman, R. Cunningham, D. A. Steplock, W. Lee-Kwon, T. L. Pallone, S. Shenolikar, and E. J. Weinman Localization and interaction of NHERF isoforms in the renal proximal tubule of the mouse Am J Physiol Cell Physiol, December 1, 2003; 285(6): C1494 - C1503. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |