Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Importance of splicing for prosaposin sorting

L Madar-Shapiro1, M Pasmanik-Chor, A M Vaccaro

  • 1Department of Cell Research and Immunology, Tel-Aviv University, Ramat Aviv 69978, Israel.

The Biochemical Journal
|January 23, 1999
PubMed
Summary

Alternative splicing of the prosaposin gene generates distinct protein forms. These forms exhibit differential cellular sorting, impacting their secretion and lysosomal localization, influencing saposin B and C activity.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Nutritional Status in Childhood as a Prognostic Factor in Patients with Cystic Fibrosis.

Lung·2019
Same author

Biogenic habitat shifts under long-term ocean acidification show nonlinear community responses and unbalanced functions of associated invertebrates.

The Science of the total environment·2019
Same author

Sodium phosphate enemas do not worsen renal function among hospitalized patients with mild to moderate renal failure: a matched, case-control study.

QJM : monthly journal of the Association of Physicians·2017
Same author

Iatrogenic superior mesenteric vein injury: the perils of high ligation.

International journal of colorectal disease·2016
Same author

Corrected QT interval anomalies are associated with worse prognosis among patients suffering from sepsis.

Internal medicine journal·2016
Same author

When uncommon and common coalesce: adult onset Still's disease associated with breast augmentation as part of autoimmune syndrome induced by adjuvants (ASIA).

Clinical rheumatology·2015

Area of Science:

  • Molecular biology
  • Cell biology
  • Biochemistry

Background:

  • The prosaposin gene encodes a 70 kDa protein with potential lysosomal or secreted functions.
  • Alternative splicing of exon 8 in the human prosaposin gene generates three distinct protein variants.
  • Prosaposins are precursors to saposins, activators of lysosomal enzymes.

Purpose of the Study:

  • To investigate the association between alternative splicing of prosaposin and its differential cellular sorting.
  • To determine how different prosaposin forms are processed and localized within human cells.

Main Methods:

  • Cloning and expression of two human prosaposin cDNA forms in a viral vector system (T7/EMC/vaccinia).
  • Expression in human cells to analyze prosaposin accumulation in the medium versus lysosomes.

Related Experiment Videos

  • In vitro mutagenesis of the 9 bp stretch in exon 8 to assess effects on secretion.
  • Endocytosis studies of secreted prosaposins.
  • Quantitative lipid analysis (TLC, fluorimetry) and qualitative fluorescence microscopy to monitor saposin activity.

    • Main Results:

    • Prosaposin with three extra residues showed faster and greater accumulation in the medium (secretion).
    • Prosaposin with no extra residues was primarily targeted to lysosomes.
    • In vitro mutations in the 9 bp stretch affected prosaposin secretion differently.
    • Both prosaposin forms, when added to the medium, were endocytosed and processed to active saposin B and saposin C in lysosomes.

    Conclusions:

    • Alternative splicing of the prosaposin gene directly influences its secretion versus lysosomal targeting.
    • The differential sorting of prosaposin variants impacts the availability and activity of saposins B and C.
    • Prosaposins can be secreted, endocytosed, and subsequently processed in lysosomes, demonstrating a flexible biological role.