This Article Order Full text via Infotrieve Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bachinsky, D. R. Articles by McCluskey, R. T. Search for Related Content PubMed PubMed Citation Articles by Bachinsky, D. R. Articles by McCluskey, R. T.

American Journal of Pathology, Vol 143, 598-611, Copyright © 1993 by American Society for Investigative Pathology

REGULAR ARTICLES

Detection of two forms of GP330. Their role in Heymann nephritis

DR Bachinsky, G Zheng, JL Niles, M McLaughlin, M Abbate, G Andres, D Brown and RT McCluskey
Department of Pathology, Massachusetts General Hospital, Charlestown 02129.

Heymann nephritis is characterized by glomerular immune deposits that contain a glycoprotein called gp330. The deposits are believed to result from shedding of immune complexes formed on podocytes. Complexes are also shed from proximal tubule cells, when antibodies combine with gp330 on the cell surface. We performed the present study to investigate what portion of the gp330 molecule is shed, using a rabbit antiserum against a peptide deduced to be in the cytoplasmic domain of gp330, as well as a rabbit antiserum and two monoclonal antibodies that recognize extracellular epitopes of gp330. The anti-cytoplasmic peptide antiserum precipitated from Fx1A (a crude renal cortical membrane preparation), a protein with a mass of about 440 kd that was reactive with two monoclonal anti-gp330 antibodies. (In our experiments, the protein called gp330 generally has a mass estimated to be about 440 kd.) The anti-cytoplasmic peptide antiserum also reacted with a truncated gp330 protein produced in transfected COS cells. Immunohistochemical studies showed that all the antibodies recognized the same group of epithelial cells. However, as seen in immunoultrastructural studies of proximal tubules, the anti-cytoplasmic peptide antiserum reacted only with components at the base of microvilli, whereas the anti-gp330 ectodomain antibodies identified material not only at the base, but over the surface of microvilli as well. In rats with Heymann nephritis, glomerular deposits and material shed into tubule lumens reacted with antibodies against extracellular epitopes of gp330, but not with the anti-cytoplasmic peptide antiserum. We propose that there are two forms of gp330 on the cell surface of proximal renal tubules. One form is restricted to coated pit regions at the base of microvilli and has a cytoplasmic domain containing a sequence deduced from a partial complementary DNA encoding gp330. The other form is present over microvilli (and possibly at the base of microvilli as well) and lacks the cytoplasmic domain deduced from the complementary DNA. The complexes that are shed in Heymann nephritis contain either a portion of gp330 cleaved from the full-length molecule or a form of gp330 that lacks the cytoplasmic domain.

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]

				Z. Zou, B. Chung, T. Nguyen, S. Mentone, B. Thomson, and D. Biemesderfer Linking Receptor-mediated Endocytosis and Cell Signaling: EVIDENCE FOR REGULATED INTRAMEMBRANE PROTEOLYSIS OF MEGALIN IN PROXIMAL TUBULE J. Biol. Chem., August 13, 2004; 279(33): 34302 - 34310. [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]

				J. Nagai, H. Tanaka, N. Nakanishi, T. Murakami, and M. Takano Role of megalin in renal handling of aminoglycosides Am J Physiol Renal Physiol, August 1, 2001; 281(2): F337 - F344. [Abstract] [Full Text] [PDF]

				E. I. Christensen and H. Birn Megalin and cubilin: synergistic endocytic receptors in renal proximal tubule Am J Physiol Renal Physiol, April 1, 2001; 280(4): F562 - F573. [Abstract] [Full Text] [PDF]

				W. Morelle, S. M. Haslam, M. Ziak, J. Roth, H. R. Morris, and A. Dell Characterization of the N-linked oligosaccharides of megalin (gp330) from rat kidney Glycobiology, March 1, 2000; 10(3): 295 - 304. [Abstract] [Full Text] [PDF]

				H. BIRN, H. VORUM, P. J. VERROUST, S. K. MOESTRUP, and E. I. CHRISTENSEN Receptor-Associated Protein Is Important for Normal Processing of Megalin in Kidney Proximal Tubules J. Am. Soc. Nephrol., February 1, 2000; 11(2): 191 - 202. [Abstract] [Full Text] [PDF]

				E. I. CHRISTENSEN and T. E. WILLNOW Essential Role of Megalin in Renal Proximal Tubule for Vitamin Homeostasis J. Am. Soc. Nephrol., October 1, 1999; 10(10): 2224 - 2236. [Full Text]

				J. R. Ingelfinger, F. Jung, D. Diamant, L. Haveran, E. Lee, A. Brem, and S.-S. Tang Rat proximal tubule cell line transformed with origin-defective SV40 DNA: autocrine ANG II feedback Am J Physiol Renal Physiol, February 1, 1999; 276(2): F218 - F227. [Abstract] [Full Text] [PDF]

				R. Czekay, R. Orlando, L Woodward, E. Adamson, and M. Farquhar The expression of megalin (gp330) and LRP diverges during F9 cell differentiation J. Cell Sci., January 4, 1995; 108(4): 1433 - 1441. [Abstract] [PDF]