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 Concept Videos

Insertion of Single-pass Transmembrane Proteins in the RER01:26

Insertion of Single-pass Transmembrane Proteins in the RER

18.7K
Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane integral proteins that span the lipid bilayer and monotopic proteins that are attached to either side of the membrane but do not pass through it.
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
18.7K
Mitochondrial Precursor Proteins01:39

Mitochondrial Precursor Proteins

3.9K
Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70  chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial...
3.9K
Tail-anchoring of Proteins in the ER Membrane01:45

Tail-anchoring of Proteins in the ER Membrane

4.0K
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
4.0K
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

13.6K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
13.6K
Protein Translocation Machinery on the ER Membrane01:28

Protein Translocation Machinery on the ER Membrane

7.2K
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
7.2K
Membrane Asymmetry Regulating Transporters01:19

Membrane Asymmetry Regulating Transporters

7.8K
Enzymes like flippase, floppase, and scramblase transfer phospholipids from one layer to another in the membrane, thereby affecting membrane asymmetry.
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
7.8K

You might also read

Related Articles

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

Sort by
Same author

Per- and polyfluoroalkyl substances (PFAS) in early life is associated with childhood intestinal inflammation: analyses of three birth cohorts.

Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association·2026
Same author

Stability-driven multi-omics integration for reproducible latent structure.

bioRxiv : the preprint server for biology·2026
Same author

The γ-secretase complex: from discovery to a therapeutic target.

RSC chemical biology·2026
Same author

Nitric oxide drives proteomic diversity through alternative splicing.

Molecular cell·2026
Same author

Predictors for T cell receptor excision circles in infants without severe combined immunodeficiency or thymic aplasia/hypoplasia.

Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology·2026
Same author

Cortisol-to-cortisone ratio postpartum is associated with anti-Müllerian hormone a decade later: evidence from a prospective study.

Endocrine connections·2026

Related Experiment Video

Updated: Mar 14, 2026

Saccharomyces cerevisiae Models of Alzheimer's Disease to Screen Genes, Mutations, and Chemicals Affecting Amyloid Beta Production by γ-Secretase
11:57

Saccharomyces cerevisiae Models of Alzheimer's Disease to Screen Genes, Mutations, and Chemicals Affecting Amyloid Beta Production by γ-Secretase

Published on: June 24, 2025

668

Transmembrane Substrate Determinants for γ-Secretase Processing of APP CTFβ.

Marty A Fernandez1, Kelly M Biette1, Georgia Dolios2

  • 1Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts 02115, United States.

Biochemistry
|September 21, 2016
PubMed
Summary

Alzheimer's disease amyloid-beta (Aβ) production by γ-secretase involves sequential cleavages within the APP transmembrane domain. Helix unwinding of the substrate is crucial for both initial cleavage and C-terminal trimming.

More Related Videos

Quantitative Measurement of γ-Secretase-mediated Amyloid Precursor Protein and Notch Cleavage in Cell-based Luciferase Reporter Assay Platforms
06:40

Quantitative Measurement of γ-Secretase-mediated Amyloid Precursor Protein and Notch Cleavage in Cell-based Luciferase Reporter Assay Platforms

Published on: January 25, 2018

7.2K
Imaging the Intracellular Trafficking of APP with Photoactivatable GFP
07:55

Imaging the Intracellular Trafficking of APP with Photoactivatable GFP

Published on: October 17, 2015

12.4K

Related Experiment Videos

Last Updated: Mar 14, 2026

Saccharomyces cerevisiae Models of Alzheimer's Disease to Screen Genes, Mutations, and Chemicals Affecting Amyloid Beta Production by γ-Secretase
11:57

Saccharomyces cerevisiae Models of Alzheimer's Disease to Screen Genes, Mutations, and Chemicals Affecting Amyloid Beta Production by γ-Secretase

Published on: June 24, 2025

668
Quantitative Measurement of γ-Secretase-mediated Amyloid Precursor Protein and Notch Cleavage in Cell-based Luciferase Reporter Assay Platforms
06:40

Quantitative Measurement of γ-Secretase-mediated Amyloid Precursor Protein and Notch Cleavage in Cell-based Luciferase Reporter Assay Platforms

Published on: January 25, 2018

7.2K
Imaging the Intracellular Trafficking of APP with Photoactivatable GFP
07:55

Imaging the Intracellular Trafficking of APP with Photoactivatable GFP

Published on: October 17, 2015

12.4K

Area of Science:

  • Molecular Biology
  • Neuroscience
  • Biochemistry

Background:

  • Alzheimer's disease (AD) pathogenesis is linked to the production of amyloid-beta (Aβ) peptides.
  • Aβ peptides are generated by sequential cleavage of the amyloid precursor protein (APP) within its transmembrane domain (TMD) by the γ-secretase complex.
  • The spectrum of Aβ lengths, particularly the ratio of Aβ42 to Aβ40, is critical in AD.

Purpose of the Study:

  • To investigate the determinants of γ-secretase specificity and efficiency in cleaving APP C-terminal fragments (CTFβ).
  • To elucidate the mechanisms underlying the generation of different Aβ peptide lengths.
  • To understand the role of substrate structure, specifically the TMD helix, in γ-secretase activity.

Main Methods:

  • Analysis of CTFβ substrate determinants, including C-terminal charge and TMD helical properties.
  • Use of peptidomimetic probes to explore γ-secretase active site pockets (S1', S2', S3').
  • Site-directed mutagenesis (deletions) around ε sites and assessment of helical instability.

Main Results:

  • The C-terminal negative charge of intermediate Aβ49 does not influence its trimming.
  • Helical instability within the CTFβ TMD significantly enhances both endoproteolysis (ε-site cleavage) and carboxypeptidase trimming.
  • CTFβ dimers are not substrates for γ-secretase endoproteolysis, and helix unwinding is essential for both cleavage steps.

Conclusions:

  • Substrate TMD helical instability is a key factor promoting γ-secretase activity and Aβ peptide generation.
  • Initial ε-site cleavage is dictated by the interaction of residues along the undimerized, single helical TMD.
  • Helix unwinding is a prerequisite for both the initial endoproteolytic cleavage and subsequent C-terminal trimming by γ-secretase.