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STMN2 — Stathmin-2
Symbol	STMN2
Full Name	Stathmin-2 (Superior Cervical Ganglion 10, SCG10)
Chromosome	8q21.13
NCBI Gene	11075
Ensembl	ENSG00000104435
OMIM	600621
UniProt	Q93045
Diseases	3Citation2024 · DOI 10.1007/s00018-024-05550-3Open reference8(/diseases/als), 3Citation2024 · DOI 10.1007/s00018-024-05550-3Open reference9(/diseases/ftd), [Alzheimer's Disease](/diseases/alzheimers), [TDP-43 Proteinopathies](/mechanisms/tdp-43-proteinopathy)
Expression	[Motor Neurons](/cell-types/motor-neurons), Cortical Neurons, Sensory Neurons, Developing CNS
Associated Diseases	Aging, Als, Amyotrophic Lateral Sclerosis, Ms, Neuropathy
KG Connections	42 edges

STMN2 (Stathmin-2)

Introduction

Stmn2 — Stathmin 2 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

STMN2 (Stathmin-2, also known as SCG10 or Superior Cervical Ganglion 10) is a gene on chromosome 8q21.13 encoding stathmin-2, a neuron-enriched phosphoprotein critical for axonal growth, maintenance, and regeneration. STMN2 belongs to the stathmin family of microtubule-regulatory proteins and is one of the most abundantly expressed genes in motor-neurons (Klim et al., 2019). The gene has emerged as one of the most important molecular links between tdp-43 dysfunction and neurodegeneration in ^{4Citation2022 · DOI 10.1172/JCI142854Open reference}0(/diseases/als), ^{4Citation2022 · DOI 10.1172/JCI142854Open reference}1(/diseases/ftd), and other TDP-43 proteinopathies.

The discovery that loss of nuclear tdp-43 leads to cryptic exon inclusion in STMN2 mRNA—resulting in truncation and loss of functional stathmin-2 protein—has transformed understanding of how tdp-43 pathology causes neurodegeneration. STMN2 is now a leading therapeutic target for ALS and related disorders, with antisense oligonucleotide (ASO) and gene therapy approaches in preclinical and early clinical development (Baughn et al., 2023; Krus et al., 2022).

Function

Microtubule Regulation

Stathmin-2 is a phosphoprotein that regulates microtubule dynamics through its stathmin-like domain. Like other stathmin family members, it can sequester tubulin dimers, reducing the pool of free tubulin available for microtubule polymerization. However, STMN2’s primary neuronal functions appear to extend beyond simple tubulin sequestration. Unlike cytoplasmic stathmin (STMN1), stathmin-2 contains an N-terminal membrane-targeting domain that anchors it to vesicular membranes, particularly in growth cones and along axons (Bhola et al., 2025).

Axonal Growth and Regeneration

STMN2 plays a critical role in axonal outgrowth during development and axonal regeneration after injury. Following sciatic nerve crush, STMN2 expression is rapidly upregulated in injured motor neurons, and the protein accumulates in regenerating growth cones. Genetic knockout of Stmn2 in mice impairs motor axon regeneration and delays functional recovery and reinnervation of neuromuscular junctions (Guerra San Juan et al., 2023). Remarkably, stathmin-2’s role in promoting axon regeneration is independent of its tubulin-binding capacity, suggesting it acts through alternative mechanisms involving membrane trafficking or signaling at the growth cone (Bhola et al., 2025).

Neuronal Survival

Beyond axonal maintenance, stathmin-2 contributes to neuronal survival signaling. Loss of STMN2 in human motor neuron cultures leads to reduced neurite outgrowth and increased vulnerability to stress. In spinal-muscular-atrophy models, STMN2 expression is reduced, and restoring its levels has neuroprotective effects, suggesting convergent vulnerability pathways across motor neuron diseases (Beri et al., 2024).

Disease Associations

TDP-43 Proteinopathies and Cryptic Splicing

The central disease mechanism linking STMN2 to neurodegeneration involves tdp-43 (encoded by [TARDBP). Under normal conditions, tdp-43 binds to a GU-rich sequence in intron 1 of STMN2 pre-mRNA and sterically blocks a cryptic splice site. When tdp-43 is depleted from the nucleus—as occurs in >97% of ^{4Citation2022 · DOI 10.1172/JCI142854Open reference}2(/diseases/als) cases and ~45% of ^{4Citation2022 · DOI 10.1172/JCI142854Open reference}3(/diseases/ftd) cases—this cryptic splice site is recognized by the spliceosome, leading to inclusion of a premature polyadenylation signal (cryptic exon 2a). The resulting truncated mRNA encodes only 17 amino acids instead of the full-length 179-amino-acid stathmin-2 protein, and the aberrant transcript is subject to rapid degradation (Klim et al., 2019; Melamed et al., 2019).

This cryptic splicing event makes STMN2 the most affected RNA target of TDP-43 loss-of-function, with near-complete abolition of functional stathmin-2 in affected neurons. The resulting loss of axonal maintenance and regeneration capacity is believed to be a major contributor to motor neuron degeneration.

Amyotrophic Lateral Sclerosis (ALS)

In ^{4Citation2022 · DOI 10.1172/JCI142854Open reference}4(/diseases/als), loss of nuclear TDP-43 with cytoplasmic inclusions is the defining pathological feature in ~97% of cases (excluding SOD1-ALS). STMN2 cryptic exon inclusion has been detected in spinal cord motor neurons of ALS patients at autopsy, correlating with reduced stathmin-2 protein levels. STMN2 cryptic exon RNA serves as a molecular marker of TDP-43 dysfunction and can be detected in cerebrospinal fluid, positioning it as a potential biomarker (Baughn et al., 2023).

Frontotemporal Dementia (FTD)

Approximately 45% of ^{4Citation2022 · DOI 10.1172/JCI142854Open reference}5(/diseases/ftd) cases show TDP-43 pathology (FTLD-TDP). In these patients, STMN2 cryptic splicing is detectable in affected cortical regions, particularly frontal and temporal cortex. The degree of STMN2 cryptic exon inclusion correlates with the burden of TDP-43 pathology (Prudencio et al., 2020).

Alzheimer’s Disease

Recent studies have expanded the relevance of STMN2 beyond classic TDP-43 proteinopathies. Cryptic splicing of both STMN2 and unc13a mRNAs has been detected in alzheimers patients with TDP-43 co-pathology (present in ~30-50% of AD cases). Importantly, STMN2 and UNC13A cryptic exon levels correlate with TDP-43 pathology burden but not with Amyloid-Beta or tau[/proteins/tau-protein deposits, suggesting an independent pathogenic contribution of TDP-43 dysfunction in AD (Agra Almeida Quadros et al., 2024).

C9orf72-Related Disease

c9orf72 repeat expansion, the most common genetic cause of ALS/FTD, also affects STMN2 expression. c9orf72 poly-PR dipeptide repeat proteins disrupt STMN2 expression through SRSF7, providing an additional mechanism of STMN2 loss independent of direct TDP-43 depletion (Pickles et al., 2025).

Expression

STMN2 is highly and preferentially expressed in neurons of the central and peripheral nervous systems. It is particularly abundant in:

• motor-neurons — among the highest expressing cell types, consistent with vulnerability in ALS

• Cortical neurons — expressed across cortical layers, with higher levels in projection neurons

• hippocampal-neurons — expressed in CA1-CA3 and dentate gyrus

• Sensory neurons — dorsal root ganglia show high expression

• Developing brain — strongly expressed during embryonic neuronal development and axon pathfinding

Expression is low or absent in non-neuronal cell types including astrocytes, oligodendrocytes, and microglia

Therapeutic Targeting

Antisense Oligonucleotides (ASOs)

The most advanced therapeutic strategy targets the STMN2 cryptic splice site directly with ASOs. By blocking the aberrant splice site in intron 1, ASOs prevent cryptic exon inclusion and restore production of full-length stathmin-2 protein, even when TDP-43 remains depleted. In preclinical studies, intrathecal ASO administration corrected Stmn2 pre-mRNA misprocessing and restored stathmin-2 levels in mouse models carrying humanized STMN2 cryptic splicing sequences (Baughn et al., 2023). QRL-201 (Quralis) is an ASO targeting STMN2 cryptic splicing currently in clinical development for ALS.

CRISPR-Based Approaches

The CRISPR effector dCasRx has been used to block STMN2 cryptic splicing in TDP-43-deficient human motor neurons, providing proof-of-concept for RNA-targeted gene therapy approaches (Baughn et al., 2023).

Gene Therapy

Direct overexpression of STMN2 via AAV vectors is another strategy under investigation, aiming to bypass the cryptic splicing defect entirely by providing an exogenous source of functional stathmin-2 protein.

Brain Atlas Resources

• Allen Brain Atlas

• Allen Human Brain Atlas: STMN2 search

• Allen Mouse Brain Atlas: STMN2 search

• Allen Cell Type Atlas

• BrainSpan Developmental Transcriptome

See Also

• [Index

External Links

• PubMed

Background

The study of Stmn2 — Stathmin 2 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.