Related Experiment Video
Updated: May 21, 2026
10:37
Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
Get1 stabilizes an open dimer conformation of get3 ATPase by binding two distinct interfaces
Keiko Kubota1, Atsushi Yamagata, Yusuke Sato
1Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, the University of Tokyo, Tokyo 113‐0032, Japan.
Journal of Molecular Biology
|June 12, 2012
Summary
The GET complex facilitates tail-anchored protein insertion into the ER membrane. New structures reveal how Get1 stabilizes the Get3 ATPase in its open state, crucial for this process.
Area of Science:
- Cell Biology
- Molecular Biology
- Membrane Protein Biogenesis
Background:
- Tail-anchored (TA) proteins are vital for cellular functions, including membrane trafficking and apoptosis.
- The Guided Entry of TA proteins (GET) complex mediates their insertion into the endoplasmic reticulum (ER) membrane post-translationally.
- The GET complex comprises the Get3 ATPase and the Get1/2 receptor, with Get3 undergoing conformational changes during TA protein binding and release.
Purpose of the Study:
- To elucidate the structural mechanisms by which the Get1 receptor interacts with and stabilizes the Get3 ATPase.
- To understand the conformational dynamics of Get3 during the TA protein insertion process.
Main Methods:
- X-ray crystallography was used to determine the structures of ADP-bound Get3 in complex with the Get1 cytoplasmic domain (Get1CD).
- Structures were obtained in both open and semi-open Get3 dimer conformations.
- Biochemical assays were performed to validate the functional roles of the observed Get1-Get3 interfaces.
Main Results:
- Crystal structures revealed Get1CD binding to Get3 in open (3.0 Å) and semi-open (4.5 Å) conformations.
- Get1 utilizes two distinct interfaces to interact with the Get3 dimer.
- Biochemical data support the structural findings regarding Get1's stabilizing role.
Conclusions:
- Get1 employs two interfaces to stabilize the open dimer conformation of Get3, a key step in TA protein biogenesis.
- One interface is sufficient for Get1 binding to Get3, while the second is critical for stabilizing the open dimer state.
Related Concept Videos
02:14GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
Large G-proteins, also known...
01:22Activation and Inactivation of G Proteins
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...
01:48ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
01:45Destabilization of Microtubules
The destabilization of microtubules can occur during different stages of the microtubule lifecycle, such as nucleation or elongation. It can take place at either end of the microtubule or in the microtubule lattices as a whole. The lifespan of individual microtubules within a cell varies according to the cell type and stage of the cell cycle. During interphase, the lifespan of the microtubule is about 30 minutes, while during cell division, it is about 15 minutes. In axonal microtubules of...
01:18ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
01:30ATP Driven Pumps III: V-type Pumps
V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...