Teaching Resource

Chloride Concentration and pH Along the Endosomal Pathway

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Science's STKE  25 May 2004:
Vol. 2004, Issue 234, pp. tr2
DOI: 10.1126/stke.2342004tr2

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  • Chloride Concentration and pH Along the Endosomal Pathway

    Victor Faundez1,2, and H. Criss Hartzell1, Elizabeth M. Adler2*

    1Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
    2Science's STKE, American Association for the Advancement of Science, Washington, DC 20005, USA.


    *Corresponding author: E-mail: E-Mail


    This animation depicts three membrane trafficking routes in a mammalian neurosecretory cell, highlighting the changing Cl concentrations and pH values of the various endosomal subcompartments. The focus is on the endocytotic pathway and the different paths taken by clathrin-coated vesicles. Once you have clicked the "Play" button to start the animation, you can choose to highlight the pathway for receptor recycling to the plasma membrane, the lysosomal pathway, or the pathway for synaptic vesicle recycling (in neurons). Each compartment shown has a distinctive pH and [Cl], with values for pH indicated in blue and values for Cl indicated in orange. The differences in each of the endocytic compartments are represented by changing colored bars at the top. The intravesicular [Cl] in synaptic vesicles, large dense core vesicles, and lysosomes has not yet been determined. Cl influx helps regulate pH in the vesicle lumen, and the changes in [Cl] and pH likely help regulate membrane trafficking. This animation will be useful for teaching cell biology and highlighting both the dynamic nature of vesicular traffic and the changes in ionic balance associated with different cellular compartments. This animation was created by Julie White, under the scientific oversight of Criss Hartzell and Victor Faundez.

    [Access Resource]

    C. Hartzell and N. Germick have created a song to represent these processes; download this music in mp3 format to accompany the animation showing endosomal trafficking [Access Music].

    Educational Details

    Learning Resource Type: Animation

    Context: Undergraduate upper division, Graduate, Professional (degree program)

    Intended Users: Teacher, learner

    Intended Educational Use: Teach, learn

    Discipline: Cell biology, neurobiology

    Keywords: movie, signal transduction, cell signaling, chloride, pH, endocytosis, synaptic vesicle, endosome

    Technical Details

    Format: Shockwave Flash Object (swf file)

    Size: 88 KB

    Requirements: Macromedia Flash 5 (http://www.macromedia.com/downloads/)

    Related Resources

    Review: V. Faundez, H. C. Hartzell, Intracellular chloride channels: Determinants of function in the endosomal pathway. Sci. STKE 2004, re8 (2004).

    Limits for Use

    Cost: Free

    Rights: This material may be downloaded, printed, linked to, and/or redistributed without modification for noncommercial, course teaching purposes only, provided credit to STKE is included by listing the citation for the teaching resource.


    Citation: V. Faundez, H. C. Hartzell, E. M. Adler, Chloride Concentration and pH Along the Endosomal Pathway. Sci. STKE2004, tr2 (2004).

    © 2004 American Association for the Advancement of Science

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