Transgelin-2 (TAGLN2) belongs to the transgelin family and its expression spans multiple tissues while showing significant presence in immune cells. Studies show TAGLN2 functions as a vital controller of cytoskeletal reorganization which affects both cell migration and signal transduction pathways. TAGLN2 belongs to the transgelin family and appears throughout multiple tissues but is most abundant in immune cells such as T cells and certain epithelial and cancer cells. TAGLN2 protein directs immune responses and controls both cellular signaling pathways and movement by managing the actin cytoskeleton structure.
Fig 1. TAGLN2 is involved in important physiological activities (Kim, H., et al. 2017).
Related Products
Overview of T Cell Activation
The immune response starts with T cell activation through T cell receptor (TCR) recognition of major histocompatibility complex (MHC) displayed on antigen presenting cells (APC) that binds to antigenic peptides. This process involves multiple signaling pathways, including:
- TCR complex signaling (such as ZAP-70, LAT, PLCγ1)
- Cytoskeleton remodeling (such as actin polymerization)
- Immunological synapse (IS) formation
Structure and Function of TAGLN2
TAGLN2 contains a standard calponin homology domain that interacts with actin to stabilize the cytoskeleton while controlling cellular morphology and dynamics. Its main functions include:
Actin Binding and Stabilization
TAGLN2 attaches to F-actin to hinder actin depolymerization and preserve cytoskeletal structure.
Regulating Cell Migration
TAGLN2 modifies cell morphology and migration capabilities while being crucial for both immune and cancer cells.
Participating in Signal Transduction
The TAGLN2 protein modifies cytoskeletal dynamics and signaling pathways by controlling the activity levels of small GTPases including RhoA, Rac1, and Cdc42.
The Role of TAGLN2 in Different Physiological Processes
Role in Immune System
The TAGLN2 gene displays high expression levels in immune cells including T cells and macrophages while playing a crucial role in controlling immune cell activation and movement and signal transmission.
| T cell activation and immune synapse formation |
TAGLN2 helps stabilize the actin structure and promotes T cell receptor (TCR) complex clustering to increase T cell responsiveness to antigens. Upon interaction with antigen presenting cells (APCs), T cells activate TAGLN2 to create immune synapses leading to enhanced T cell activation and cytokine production. |
| Affecting T cell calcium signaling (Ca²⁺ signaling) |
The activity of TAGLN2 enhances T cell calcium signaling via STIM1-Orai1-mediated calcium influx resulting in T cell activation and improved effector functions. |
| Influencing immune cell migration |
TAGLN2 controls actin structure changes to guide T cells and both macrophages and dendritic cells towards chemotaxis which supports inflammatory processes and immune monitoring. |
Role in Cancer
TAGLN2 shows abnormal expression levels across various cancer types and supports tumor advancement through its impact on tumor cell migration capabilities and immune system evasion.
| Promote cancer cell migration and invasion |
The RhoA/ROCK signaling pathway regulation by TAGLN2 boosts cancer cells' invasive ability. TAGLN2 overexpression correlates with negative outcomes in several tumor types including lung cancer, colorectal cancer and breast cancer. |
| Affecting the tumor immune microenvironment |
TAGLN2 participates in tumor immune evasion through its impact on T cell attack capability on cancer cells. Research indicates that blocking TAGLN2 expression strengthens T cells' ability to destroy tumor cells which marks a potential new cancer immunotherapy target. |
Other Physiological Processes
| Cell division and proliferation |
TAGLN2 potentially regulates the cell cycle and influences how actin changes dynamically during cell division. |
| Participate in angiogenesis |
TAGLN2's regulation of the actin skeleton enables it to impact endothelial cell migration and proliferation thereby influencing the angiogenesis process. |
| Participate in nervous system function |
TAGLN2 has been identified as having involvement in neuron synaptic plasticity and axon growth yet its precise mechanisms remain unknown. |
TAGLN2 Functions to Enable T Cell Activation
Ensure Actin Skeleton Stability Supporting Immune Synapse development
T cells activate when immune synapses form between them and other cells. TAGLN2 enables T cells to establish close contact with antigen presenting cells (APCs) through its control over the actin cytoskeleton's dynamic changes. Research indicates that TAGLN2 interacts directly with actin to stabilize it while promoting TCR aggregation and boosting T cell sensitivity toward antigen stimulation.
Promote TCR Signal Transduction
TAGLN2 is involved in TCR complex signal transduction which modulates ZAP-70 kinase phosphorylation levels thereby boosting downstream signaling processes that activate ERK, NF-κB and NFAT. The absence of TAGLN2 leads to weaker TCR-mediated signal transduction which reduces IL-2 production and impairs T cell proliferation and effector function.
TAGLN2 Modify T cell Behavior by Controlling Calcium Dignaling Pathways
The activation state of T cells depends on how TAGLN2 regulates the Ca²⁺ signaling pathway. TAGLN2 facilitates calcium entry through STIM1 and Orai1 channels which leads to increased T cell activation and cytokine emission.
Potential Role of TAGLN2 in Immune-related Diseases
TAGLN2 functions as a key mediator in T cell activation which indicates its potential involvement in various immune disorders.
- Autoimmune diseases (such as rheumatoid arthritis, multiple sclerosis): When TAGLN2 becomes hyperactive it causes abnormal T cell function that triggers immunopathological responses.
- Cancer immune escape: Tumors use a strategy to suppress TAGLN2 expression which reduces T cell activity and helps them evade the immune system.
- Infectious diseases: TAGLN2 could influence how T cells respond to viral and bacterial infections.
TAGLN2: An Important Regulator of T Cell Activation
As a crucial regulator of T cell activation TAGLN2 impacts immune response through its effects on actin skeleton dynamics TCR signaling pathways and Ca²⁺ mobilization. Research that deeply explores TAGLN2's mechanism will generate immune regulation strategies to treat cancer and both infectious and autoimmune diseases.
References
- Kim, H., et al. An essential role for TAGLN2 in phagocytosis of lipopolysaccharide-activated macrophages. Scientific Reports. 2017, 7(1): 8731.
- Han, M., et al. TAGLN2 is a candidate prognostic biomarker promoting tumorigenesis in human gliomas. Journal of Experimental & Clinical Cancer Research. 2017, 36: 1-14.
.
