Mechanically gated channel activity in cytoskeleton-deficient plasma membrane blebs and vesicles from Xenopus oocytes

Yong Zhang, Feng Gao, Vsevolod Popov, Julie W. Wen, Owen Hamill

Research output: Contribution to journalArticle

75 Citations (Scopus)

Abstract

1. A novel technique involving hypertonic stress causes membrane 'blebbing' of the Xenopus oocyte and the shedding of plasma membrane vesicles (PMVs). 2. Confocal fluorescence microscopy, immunocytochemistry and electron microscopy indicate that blebs and PMVs lack cortical cytoskeleton and are deficient in cytoskeleton proteins and devoid of microvilli. 3. Patch recordings from PMVs consistently reveal mechanically gated (MG) channel activity. The MG channels display the same single-channel conductance as control recordings but differ in terms of reduced mechanosensitivity and adaptation to sustained stimulation. 4. Whole PMV recordings show rapid and reversible activation of mechanosensitive currents in response to pressure pulses. The maximal currents activated in PMVs are consistent with MG channel activity recorded in patches. 5. The discrepancy between MG channel activity recorded in whole PMVs and oocytes most probably reflects their different membrane geometry and ability to develop activating bilayer tensions. 6. We propose that membrane blebbing, which is known to occur under specific physiological and pathological conditions (e.g. mitosis and apoptosis), may increase mechanosensitivity independently of the intrinsic properties of membrane proteins.

Original languageEnglish (US)
Pages (from-to)117-130
Number of pages14
JournalJournal of Physiology
Volume523
Issue number1
StatePublished - Feb 15 2000

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Blister
Xenopus
Cytoskeleton
Oocytes
Cell Membrane
Membranes
Osmotic Pressure
Microvilli
Fluorescence Microscopy
Mitosis
Confocal Microscopy
Electron Microscopy
Membrane Proteins
Immunohistochemistry
Apoptosis
Blood Pressure
Proteins

ASJC Scopus subject areas

  • Physiology

Cite this

Mechanically gated channel activity in cytoskeleton-deficient plasma membrane blebs and vesicles from Xenopus oocytes. / Zhang, Yong; Gao, Feng; Popov, Vsevolod; Wen, Julie W.; Hamill, Owen.

In: Journal of Physiology, Vol. 523, No. 1, 15.02.2000, p. 117-130.

Research output: Contribution to journalArticle

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