Related Experiment Video

Updated: May 5, 2026

Visualization of Endogenous Mitophagy Complexes In Situ in Human Pancreatic Beta Cells Utilizing Proximity Ligation Assay
08:40

Visualization of Endogenous Mitophagy Complexes In Situ in Human Pancreatic Beta Cells Utilizing Proximity Ligation Assay

Published on: May 2, 2019

5.5K

Expression, phosphorylation and function of the Rab-GTPase activating protein TBC1D1 in pancreatic beta-cells

Sabine Rütti1, Caroline Arous1, Alexandra C Nica1

  • 1Department of Genetic Medicine and Development, University Medical Center, University of Geneva, Geneva, Switzerland.

FEBS Letters
|November 19, 2013
PubMed

Insights

The Rab-GTPase activating protein TBC1D1 is expressed in beta-cells and influences insulin release and proliferation. Its role in beta-cell function and survival is now clearer.

Area of Science:

  • Endocrinology
  • Molecular Biology
  • Cell Biology

Background:

  • TBC1D1 is a Rab-GTPase activating protein and paralog of AS160/TBC1D4.
  • AS160/TBC1D4 is crucial for beta-cell function and survival, acting as a downstream effector of Akt.
  • The expression and function of TBC1D1 in beta-cells were previously unknown.

Purpose of the Study:

  • To determine if TBC1D1 is expressed in beta-cells.
  • To investigate the role of TBC1D1 in beta-cell function and survival.
  • To compare TBC1D1's role with that of AS160/TBC1D4.

Main Methods:

  • Utilized human and rat beta-cells.
  • Examined TBC1D1 expression and phosphorylation in response to glucose.
  • Performed TBC1D1 knockdown experiments in beta-cells.

Main Results:

  • TBC1D1 is expressed and phosphorylated in response to glucose in beta-cells.
  • TBC1D1 knockdown led to increased basal and glucose-stimulated insulin release.
  • TBC1D1 knockdown resulted in decreased beta-cell proliferation but did not affect apoptosis.

Conclusions:

  • TBC1D1 is present and regulated by glucose in beta-cells.
  • TBC1D1 plays a significant role in modulating insulin secretion and beta-cell proliferation.
  • TBC1D1 is a novel factor influencing beta-cell physiology.
Keywords:
ApoptosisBeta-cellGlucose responseProliferationTBC1D1

More Related Videos

A High-content In Vitro Pancreatic Islet β-cell Replication Discovery Platform09:35

A High-content In Vitro Pancreatic Islet β-cell Replication Discovery Platform

Published on: July 16, 2016

10.4K
Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells06:54

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells

Published on: October 27, 2020

13.1K

Related Concept Videos

PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a...
5.2K
TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors...
7.2K
Insulin Secretory Vesicles01:05

Insulin Secretory Vesicles

Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
6.3K
Rab Proteins01:14

Rab Proteins

Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
4.1K
cAMP-dependent Protein Kinase Pathways01:25

cAMP-dependent Protein Kinase Pathways

Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
7.3K
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion01:27

Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are...
2.8K