Related Experiment Video

Updated: Jan 18, 2026

Visualizing Neuroblast Cytokinesis During C. elegans Embryogenesis
09:52

Visualizing Neuroblast Cytokinesis During C. elegans Embryogenesis

Published on: March 12, 2014

12.3K

Loss of myosin Vb promotes apical bulk endocytosis in neonatal enterocytes

Amy C Engevik1,2, Izumi Kaji1,2, Meagan M Postema2

  • 1Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN.

The Journal of Cell Biology
|September 29, 2019
PubMed

Insights

Inclusions in microvillus inclusion disease form via apical bulk endocytosis in myosin Vb (Myo5B) knockout enterocytes. This process involves invagination of the apical membrane, similar to synaptic vesicle uptake.

Area of Science:

  • Cell Biology
  • Gastroenterology
  • Molecular Medicine

Background:

  • Microvillus inclusion disease (MVID) is characterized by enterocyte inclusions, but their origin is unknown.
  • Inactivating mutations in myosin Vb (Myo5B) cause MVID, leading to enterocyte inclusions lined by microvilli.

Purpose of the Study:

  • To investigate the origin of intracellular inclusions in enterocytes of Myo5b knockout (KO) mice.

Main Methods:

  • Utilized Myo5b KO mouse intestinal explants and enteroids.
  • Applied live imaging and fluorescent dextran uptake assays.
  • Investigated the role of Pacsin 2 (Syndapin 2) in inclusion formation.

Main Results:

  • Confirmed inclusion formation from apical membrane invagination in Myo5b KO enterocytes.
  • Demonstrated that 70-kD FITC-dextran uptake into inclusions occurs apically.
  • Showed that inclusions contain VAMP4 and Pacsin 2, with double KO mice exhibiting reduced inclusion formation.

Conclusions:

  • Apical bulk endocytosis mediates inclusion formation in neonatal Myo5b KO enterocytes.
  • This mechanism resembles activity-dependent bulk endocytosis observed in neuronal tissues.
  • Findings elucidate the cellular basis of MVID pathogenesis.

More Related Videos

In Vitro Apical-Out Enteroid Model of Necrotizing Enterocolitis09:11

In Vitro Apical-Out Enteroid Model of Necrotizing Enterocolitis

Published on: June 8, 2022

2.7K
En Face Endocardial Cushion Preparation for Planar Morphogenesis Analysis in Mouse Embryos08:57

En Face Endocardial Cushion Preparation for Planar Morphogenesis Analysis in Mouse Embryos

Published on: July 27, 2022

2.1K

Related Concept Videos

Cell Motility through Blebbing01:16

Cell Motility through Blebbing

Blebs are a type of membrane protrusion formed by the internal hydrostatic pressure of the cytoplasm. Blebs are observed in several cell types, including fibroblasts, immune cells, and single-celled organisms like the amoeba. The primary function of blebs is cell locomotion and apoptosis, but they are also found during necrosis and cell division. The life cycle of a bleb comprises an initiation phase followed by the expansion and retraction phases.
Blebbing Through the Matrix
In multicellular...
2.4K
Overview of Secretory Vesicles01:33

Overview of Secretory Vesicles

Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
9.4K
Role of Myosin in Cell Migration01:18

Role of Myosin in Cell Migration

Myosins are multimeric motor proteins involved in various cellular processes such as migration, adhesion, and proliferation. Myosin II is the most common type in animal cells, which binds and cross-links actin filaments.
Myosin II  is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction....
3.2K
Intralumenal Vesicles and Multivesicular Bodies01:38

Intralumenal Vesicles and Multivesicular Bodies

Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
4.7K
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR...
2.8K
Maturation of Endosomes01:28

Maturation of Endosomes

The early endosome containing internalized molecules matures through transformations in its location, morphology, intraluminal pH, and membrane protein composition. Together, these changes result in a more acidic late endosome that contains multiple intraluminal vesicles; therefore, the late endosome is also called a multivesicular body (MVB).
Changes in location
The maturing endosome moves along microtubules from the periphery of the cell towards the perinuclear region. This movement of the...
5.6K