Human GFAP-derived minimal astrocyte-specific GfaABC1D promoter
Truncated 681 bp derivative of the human GFAP promoter, combining the A, B, C1, and D regulatory regions of the 2.2 kb gfa2 fragment. Reproduces gfa2's astrocyte-restricted expression pattern at about twofold greater activity while freeing substantial cargo space, making it the preferred GFAP-family promoter for AAV vectors where packaging capacity is limited.
Origin: Human GFAP gene, truncated 681 bp gfa2 derivative (A/B/C1/D regions)
Characteristics
Truncated derivative of the 2.2 kb human gfa2 GFAP fragment, retaining the A, B, C1, and D regulatory regions while removing intervening sequence. In transgenic mice, gfaABC1D reproduces essentially the same astrocyte-restricted expression pattern as full-length gfa2 but with about twofold greater activity. In AAV vectors, GFAP-family promoter constructs including this derivative can drive detectable off-target expression in a subset of cortical neurons, with the degree of leakage varying by brain region and increasing at high viral titers.
Applications: Standard compact promoter for astrocyte-restricted transgene expression in AAV vectors where packaging capacity is limited, including reactive-astrogliosis reporters and CNS astrocyte-targeted gene delivery in rodent models.
Limitations: Not fully astrocyte-restricted in AAV vectors — off-target expression in a subset of cortical neurons occurs and increases at high viral titers, with the degree of leakage varying by brain region. Still larger than some minimal cell-type-specific promoters, though substantially more compact than the full-length 2.2 kb gfa2 fragment.
Sequence
References
- Brenner et al. (1994). GFAP promoter directs astrocyte-specific expression in transgenic mice. J Neurosci - Brenner 1994 GFAP Astrocyte