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Receptor-mediated internalization of bradykinin : DDT1 MF-2 smooth muscle cells process internalized bradykinin via multiple degradative pathways

Munoz, Consuelo M. and Leeb-Lundberg, L. M Fredrik LU (1992) In Journal of Biological Chemistry 267(1). p.303-309
Abstract

This study was undertaken to evaluate the role of internalization in the action of the peptide autacoid bradykinin (BK). At 4°C [3H]BK binds to an apparently single class of B2 kinin receptors on DDT1 MF-2 smooth muscle cells (C. M. Munoz, S. Cotecchia, and L. M. F. Leeb-Lundberg, manuscript submitted). At this temperature the [3H]BK binding was confined exclusively to the cell surface. On the other hand, at 37°C the B2 receptor-specific cell surface [3H]BK binding was rapidly followed by a receptor-specific internalization of [3H]BK (t1/2 ∼ 9 min). The internalization reached a steady-state level after 30-40 min that was 80-100% of the level of specifically bound... (More)

This study was undertaken to evaluate the role of internalization in the action of the peptide autacoid bradykinin (BK). At 4°C [3H]BK binds to an apparently single class of B2 kinin receptors on DDT1 MF-2 smooth muscle cells (C. M. Munoz, S. Cotecchia, and L. M. F. Leeb-Lundberg, manuscript submitted). At this temperature the [3H]BK binding was confined exclusively to the cell surface. On the other hand, at 37°C the B2 receptor-specific cell surface [3H]BK binding was rapidly followed by a receptor-specific internalization of [3H]BK (t1/2 ∼ 9 min). The internalization reached a steady-state level after 30-40 min that was 80-100% of the level of specifically bound [3H]BK on the cell surface at 4°C, and this level was maintained for ≥2 h. Internalized [3H]BK was routed via at least two intracellular degradative pathways which were distinguished primarily based on subcellular localization but also on a small but significant difference in the rate of [3H]BK degradation. One pathway was localized in a plasma membrane-enriched fraction and had a relatively high degradative capacity. Another pathway was localized in a microsomal fraction and had a relatively low degradative capacity. The internalized [3H]BK activity was rapidly released into the media (t1/2 ∼ 24 min). Following a single round of internalization, the released activity consisted almost exclusively of small [3H]BK fragments (<[3H]BK(1-5)). In contrast, at steady-state [3H]BK represented 30-40% of the released activity. While chloroquine (100 μM) did not alter the rate of [3H]BK internalization or release or the intracellular distribution of [3H] BK, this agent significantly decreased the rate of [3H] BK degradation in both pathways. In all, these results show that B2 kinin receptor-mediated internalization of BK is a process integral to the interaction of BK with DDT1 MF-2 smooth muscle cells and may be a mechanism for terminating BK actions by rapidly removing extracellular free and receptor-bound BK and accessing various intracellular BK degradative pathways.

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author
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publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biological Chemistry
volume
267
issue
1
pages
303 - 309
publisher
American Society for Biochemistry and Molecular Biology
external identifiers
  • scopus:0026531241
  • pmid:1309739
ISSN
0021-9258
language
English
LU publication?
no
id
58204bfa-bfdd-494d-bdc3-d3251724a460
alternative location
http://www.jbc.org/content/267/1/303.full.pdf+html
date added to LUP
2019-06-12 11:47:49
date last changed
2024-01-01 09:53:59
@article{58204bfa-bfdd-494d-bdc3-d3251724a460,
  abstract     = {{<p>This study was undertaken to evaluate the role of internalization in the action of the peptide autacoid bradykinin (BK). At 4°C [<sup>3</sup>H]BK binds to an apparently single class of B2 kinin receptors on DDT<sub>1</sub> MF-2 smooth muscle cells (C. M. Munoz, S. Cotecchia, and L. M. F. Leeb-Lundberg, manuscript submitted). At this temperature the [<sup>3</sup>H]BK binding was confined exclusively to the cell surface. On the other hand, at 37°C the B2 receptor-specific cell surface [<sup>3</sup>H]BK binding was rapidly followed by a receptor-specific internalization of [<sup>3</sup>H]BK (t<sub>1/2</sub> ∼ 9 min). The internalization reached a steady-state level after 30-40 min that was 80-100% of the level of specifically bound [<sup>3</sup>H]BK on the cell surface at 4°C, and this level was maintained for ≥2 h. Internalized [<sup>3</sup>H]BK was routed via at least two intracellular degradative pathways which were distinguished primarily based on subcellular localization but also on a small but significant difference in the rate of [<sup>3</sup>H]BK degradation. One pathway was localized in a plasma membrane-enriched fraction and had a relatively high degradative capacity. Another pathway was localized in a microsomal fraction and had a relatively low degradative capacity. The internalized [<sup>3</sup>H]BK activity was rapidly released into the media (t<sub>1/2</sub> ∼ 24 min). Following a single round of internalization, the released activity consisted almost exclusively of small [<sup>3</sup>H]BK fragments (&lt;[<sup>3</sup>H]BK(1-5)). In contrast, at steady-state [<sup>3</sup>H]BK represented 30-40% of the released activity. While chloroquine (100 μM) did not alter the rate of [<sup>3</sup>H]BK internalization or release or the intracellular distribution of [<sup>3</sup>H] BK, this agent significantly decreased the rate of [<sup>3</sup>H] BK degradation in both pathways. In all, these results show that B2 kinin receptor-mediated internalization of BK is a process integral to the interaction of BK with DDT<sub>1</sub> MF-2 smooth muscle cells and may be a mechanism for terminating BK actions by rapidly removing extracellular free and receptor-bound BK and accessing various intracellular BK degradative pathways.</p>}},
  author       = {{Munoz, Consuelo M. and Leeb-Lundberg, L. M Fredrik}},
  issn         = {{0021-9258}},
  language     = {{eng}},
  month        = {{12}},
  number       = {{1}},
  pages        = {{303--309}},
  publisher    = {{American Society for Biochemistry and Molecular Biology}},
  series       = {{Journal of Biological Chemistry}},
  title        = {{Receptor-mediated internalization of bradykinin : DDT1 MF-2 smooth muscle cells process internalized bradykinin via multiple degradative pathways}},
  url          = {{http://www.jbc.org/content/267/1/303.full.pdf+html}},
  volume       = {{267}},
  year         = {{1992}},
}