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. 1984 Nov;46(5):573–586. doi: 10.1016/S0006-3495(84)84056-4

Diffusion-limited forward rate constants in two dimensions. Application to the trapping of cell surface receptors by coated pits.

B Goldstein, R Griego, C Wofsy
PMCID: PMC1435053  PMID: 6149773

Abstract

A variety of receptors are known to aggregate in specialized cell surface structures called coated pits, prior to being internalized when the coated pits close off. At 37 degrees C on human fibroblasts, as well as on other cell types, a recycling process maintains a constant number of coated pits on the cell surface. In this paper, we explore implications for receptor aggregation and internalization of the two types of recycling models that have been proposed for the maintenance of the coated pit concentration. In one model, coated pits alternate between accessible and inaccessible states at fixed locations on the cell surface, while in the other model, coated pits recycle to random locations on the cell surface. We consider receptors that are randomly inserted in the membrane, move by pure diffusion with diffusion coefficient D, and are instantly and irreversibly trapped when they reach a coated pit boundary (the diffusion limit). For such receptors, we calculate for each of the two models: the mean time tau to reach a coated pit, the forward rate constant k+ for the interaction of a receptor with a coated pit, and the fraction phi of receptors aggregated in coated pits. We show that for the parameters that characterize coated pits on human fibroblasts, the way in which coated pits return to the surface has a negligible effect on the values of tau, k+, and phi for mobile receptors, D greater than or equal to 1.0 X 10(-11) cm2/s, but has a substantial effect for "immobile" receptors, D much less than 1 X 10(-11) cm2/s. We present numerical examples to show that it may be possible to distinguish between these models if one can monitor slowly diffusing receptors (D less than 1 X 10(-11) cm2/s) on cells whose coated pits have relatively short lifetimes (less than or equal to 1 min). Finally, we show that for the low-density lipoprotein (LDL) receptor on human fibroblasts (D = 4.5 X 10(-11) cm2/s), the predicted and observed values of K+ and phi are in close agreement. Therefore, even for slowly diffusing LDL receptor, unaided diffusion as the transport mechanism of receptors to coated pits is consistent with measured rates of LDL internalization.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Anderson R. G., Brown M. S., Beisiegel U., Goldstein J. L. Surface distribution and recycling of the low density lipoprotein receptor as visualized with antireceptor antibodies. J Cell Biol. 1982 Jun;93(3):523–531. doi: 10.1083/jcb.93.3.523. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Anderson R. G., Brown M. S., Goldstein J. L. Role of the coated endocytic vesicle in the uptake of receptor-bound low density lipoprotein in human fibroblasts. Cell. 1977 Mar;10(3):351–364. doi: 10.1016/0092-8674(77)90022-8. [DOI] [PubMed] [Google Scholar]
  3. Anderson R. G., Goldstein J. L., Brown M. S. A mutation that impairs the ability of lipoprotein receptors to localise in coated pits on the cell surface of human fibroblasts. Nature. 1977 Dec 22;270(5639):695–699. doi: 10.1038/270695a0. [DOI] [PubMed] [Google Scholar]
  4. Anderson R. G., Goldstein J. L., Brown M. S. Localization of low density lipoprotein receptors on plasma membrane of normal human fibroblasts and their absence in cells from a familial hypercholesterolemia homozygote. Proc Natl Acad Sci U S A. 1976 Jul;73(7):2434–2438. doi: 10.1073/pnas.73.7.2434. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Anderson R. G., Vasile E., Mello R. J., Brown M. S., Goldstein J. L. Immunocytochemical visualization of coated pits and vesicles in human fibroblasts: relation to low density lipoprotein receptor distribution. Cell. 1978 Nov;15(3):919–933. doi: 10.1016/0092-8674(78)90276-3. [DOI] [PubMed] [Google Scholar]
  6. Barak L. S., Webb W. W. Diffusion of low density lipoprotein-receptor complex on human fibroblasts. J Cell Biol. 1982 Dec;95(3):846–852. doi: 10.1083/jcb.95.3.846. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Berg H. C., Purcell E. M. Physics of chemoreception. Biophys J. 1977 Nov;20(2):193–219. doi: 10.1016/S0006-3495(77)85544-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Brown M. S., Anderson R. G., Goldstein J. L. Recycling receptors: the round-trip itinerary of migrant membrane proteins. Cell. 1983 Mar;32(3):663–667. doi: 10.1016/0092-8674(83)90052-1. [DOI] [PubMed] [Google Scholar]
  9. Brown M. S., Goldstein J. L. Analysis of a mutant strain of human fibroblasts with a defect in the internalization of receptor-bound low density lipoprotein. Cell. 1976 Dec;9(4 Pt 2):663–674. doi: 10.1016/0092-8674(76)90130-6. [DOI] [PubMed] [Google Scholar]
  10. Carpentier J. L., Gorden P., Anderson R. G., Goldstein J. L., Brown M. S., Cohen S., Orci L. Co-localization of 125I-epidermal growth factor and ferritin-low density lipoprotein in coated pits: a quantitative electron microscopic study in normal and mutant human fibroblasts. J Cell Biol. 1982 Oct;95(1):73–77. doi: 10.1083/jcb.95.1.73. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Carpentier J. L., Gorden P., Goldstein J. L., Anderson R. G., Brown M. S., Orci L. Binding and internalization of 125I-LDL in normal and mutant human fibroblasts. A quantitative autoradiographic study. Exp Cell Res. 1979 Jun;121(1):135–142. doi: 10.1016/0014-4827(79)90453-1. [DOI] [PubMed] [Google Scholar]
  12. Davies P. F., Kuczera L. Endocytic vesicles and surface invaginations in cultured vascular endothelium: a morphometric comparison. J Histochem Cytochem. 1981 Dec;29(12):1437–1441. doi: 10.1177/29.12.6172467. [DOI] [PubMed] [Google Scholar]
  13. Fan J. Y., Carpentier J. L., Gorden P., Van Obberghen E., Blackett N. M., Grunfeld C., Orci L. Receptor-mediated endocytosis of insulin: role of microvilli, coated pits, and coated vesicles. Proc Natl Acad Sci U S A. 1982 Dec;79(24):7788–7791. doi: 10.1073/pnas.79.24.7788. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Goldstein B., Wofsy C. Analysis of coated pit recycling on human fibroblasts. Cell Biophys. 1981 Sep;3(3):251–277. doi: 10.1007/BF02782627. [DOI] [PubMed] [Google Scholar]
  15. Goldstein B., Wofsy C., Bell G. Interactions of low density lipoprotein receptors with coated pits on human fibroblasts: estimate of the forward rate constant and comparison with the diffusion limit. Proc Natl Acad Sci U S A. 1981 Sep;78(9):5695–5698. doi: 10.1073/pnas.78.9.5695. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Goldstein J. L., Anderson R. G., Brown M. S. Coated pits, coated vesicles, and receptor-mediated endocytosis. Nature. 1979 Jun 21;279(5715):679–685. doi: 10.1038/279679a0. [DOI] [PubMed] [Google Scholar]
  17. Goldstein J. L., Brown M. S. Binding and degradation of low density lipoproteins by cultured human fibroblasts. Comparison of cells from a normal subject and from a patient with homozygous familial hypercholesterolemia. J Biol Chem. 1974 Aug 25;249(16):5153–5162. [PubMed] [Google Scholar]
  18. Heuser J. Three-dimensional visualization of coated vesicle formation in fibroblasts. J Cell Biol. 1980 Mar;84(3):560–583. doi: 10.1083/jcb.84.3.560. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Orci L., Carpentier J. L., Perrelet A., Anderson R. G., Goldstein J. L., Brown M. S. Occurrence of low density lipoprotein receptors within large pits on the surface of human fibroblasts as demonstrated by freeze-etching. Exp Cell Res. 1978 Apr;113(1):1–13. doi: 10.1016/0014-4827(78)90081-2. [DOI] [PubMed] [Google Scholar]
  20. Petersen O. W., van Deurs B. Serial-section analysis of coated pits and vesicles involved in adsorptive pinocytosis in cultured fibroblasts. J Cell Biol. 1983 Jan;96(1):277–281. doi: 10.1083/jcb.96.1.277. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Schlessinger J., Shechter Y., Cuatrecasas P., Willingham M. C., Pastan I. Quantitative determination of the lateral diffusion coefficients of the hormone-receptor complexes of insulin and epidermal growth factor on the plasma membrane of cultured fibroblasts. Proc Natl Acad Sci U S A. 1978 Nov;75(11):5353–5357. doi: 10.1073/pnas.75.11.5353. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Vermeer B. J., Havekes L., Wijsman M. C., Emeis J. J. Immunoelectronmicroscopical investigations on the adsorptive endocytosis of low density lipoproteins by human fibroblasts. Exp Cell Res. 1980 Sep;129(1):201–210. doi: 10.1016/0014-4827(80)90343-2. [DOI] [PubMed] [Google Scholar]
  23. Wall D. A., Hubbard A. L. Galactose-specific recognition system of mammalian liver: receptor distribution on the hepatocyte cell surface. J Cell Biol. 1981 Sep;90(3):687–696. doi: 10.1083/jcb.90.3.687. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Willingham M. C., Haigler H. T., Fitzgerald D. J., Gallo M. G., Rutherford A. V., Pastan I. H. The morphologic pathway of binding and internalization of epidermal growth factor in cultured cells. Studies on A431, KB, and 3T3 cells, using multiple methods of labelling. Exp Cell Res. 1983 Jun;146(1):163–175. doi: 10.1016/0014-4827(83)90334-8. [DOI] [PubMed] [Google Scholar]
  25. Willingham M. C., Maxfield F. R., Pastan I. H. alpha 2 Macroglobulin binding to the plasma membrane of cultured fibroblasts. Diffuse binding followed by clustering in coated regions. J Cell Biol. 1979 Sep;82(3):614–625. doi: 10.1083/jcb.82.3.614. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Willingham M. C., Pastan I. Formation of receptosomes from plasma membrane coated pits during endocytosis: analysis by serial sections with improved membrane labeling and preservation techniques. Proc Natl Acad Sci U S A. 1983 Sep;80(18):5617–5621. doi: 10.1073/pnas.80.18.5617. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Willingham M. C., Pastan I. The receptosome: an intermediate organelle of receptor mediated endocytosis in cultured fibroblasts. Cell. 1980 Aug;21(1):67–77. doi: 10.1016/0092-8674(80)90115-4. [DOI] [PubMed] [Google Scholar]
  28. Willingham M. C., Rutherford A. V., Gallo M. G., Wehland J., Dickson R. B., Schlegel R., Pastan I. H. Receptor-mediated endocytosis in cultured fibroblasts: cryptic coated pits and the formation of receptosomes. J Histochem Cytochem. 1981 Sep;29(9):1003–1013. doi: 10.1177/29.9.6169759. [DOI] [PubMed] [Google Scholar]

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