LIM domain protein TES changes its conformational states in different cellular compartments
Yingli Zhong1, Jiaolian Zhu, Yan Wang
1Key Laboratory of Protein Chemistry and Developmental Biology of Education Ministry of China, College of Life Science, Hunan Normal University, Changsha, Hunan 410081, People's Republic of China.
Molecular and Cellular Biochemistry
|August 13, 2008
Summary
The human TESTIN (TES) protein exhibits distinct conformational states, potentially influencing its cellular localization. A "closed" conformation of TES may play a role in its presence within the nucleolus.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- The human TESTIN (TES) protein is implicated as a tumor suppressor.
- TES localizes to the cytoplasm, specifically in focal adhesions and cell contacts.
- TES possesses a unique structure with an NH(2)-terminal PET domain and a COOH-terminal LIM domain.
Purpose of the Study:
- To investigate the different conformational states of the TES protein.
- To explore the relationship between TES conformation and its cellular distribution.
- To determine if intramolecular interactions within TES influence its conformation.
Main Methods:
- GST pull-down assays to test for interactions between TES termini.
- Generation of antisera against full-length and truncated TES variants.
- Co-immunoprecipitation (co-IP) to analyze protein complex formation.
- Immunofluorescence to examine cellular localization of TES.
Main Results:
- Confirmed interaction between the NH(2)-terminus and the third LIM domain of TES.
- Demonstrated co-localization of TES with the nucleolar marker B23, in addition to ER localization.
- Co-IP analysis revealed TES and B23 exist within the same protein complex.
- Antisera recognized different regions of TES, supporting distinct conformations.
Conclusions:
- TES protein exhibits distinct conformational states.
- These conformational states correlate with different cellular compartments, including the nucleolus and ER.
- A "closed" conformational state of TES is potentially involved in its nucleolar localization.
Related Concept Videos
02:26Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
01:18Membrane Domains
The membrane domains concentrate specific lipids and proteins at one place within the membrane, which helps in cell signaling, adhesion, and other critical cellular processes. These domains can differ in size, composition, function, and lifespan.
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
01:49Conserved Binding Sites
Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function.
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
01:58Mechanical Protein Functions
Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.
01:28Protein Translocation Machinery on the ER Membrane
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 translocon complex.
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 translocon complex.
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.