Progranulin Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| Progranulin (PGRN) | |
|---|---|
| Gene | GRN |
| UniProt ID | P28799 |
| Alternative Names | Granulin, PC Cell-Derived Growth Factor (PCDGF), Acrogranin |
| Molecular Weight | ~90 kDa (secreted glycoprotein) |
| Structure | 7.5 granulin repeats, cysteine-rich domains |
| Expression | Ubiquitous; highest in brain, immune cells |
| Family | Granulin family |
| Associated Diseases | FTD, ALS, PD |
Progranulin (PGRN) is a secreted glycoprotein encoded by the GRN gene that plays critical roles in development, wound healing, inflammation, and neuronal survival. It is a precursor protein consisting of 7.5 tandem granulin repeats, each approximately 60 amino acids in length with 12 conserved cysteine residues forming disulfide bonds. PGRN is cleaved by extracellular proteases (including elastase, MMP-9, and MMP-12) into active granulin peptides, which have distinct biological functions.
The progranulin protein contains:
The three-dimensional structure reveals a twisted β-helix fold common to cysteine-rich repeat proteins. Each granulin repeat forms a compact domain with the cysteine pattern creating a stable disulfide-bonded framework.
In the central nervous system, progranulin is expressed in:
Progranulin functions as a neurotrophic factor, supporting:
Heterozygous GRN mutations (dominant, haploinsufficiency) are a major cause of familial frontotemporal dementia, accounting for ~5-10% of all FTD cases. Over 70 pathogenic mutations have been identified, most leading to premature termination codons and complete loss of functional protein (null allele).
Mechanisms:
Clinical phenotype:
GRN mutations are also associated with ALS, either alone or in combination with FTD:
While not a primary cause, progranulin may play a role in PD:
| Agent | Company | Approach | Status |
|---|---|---|---|
| AAV9-GRN | Passage Bio | Gene therapy | Phase 1/2 (completed) |
| AL046 | Alector | Antibody | Phase 1 |
| PRG-001 | -- | Recombinant protein | Preclinical |
The study of Progranulin Protein 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.
Baker M, et al. (2006). Mutations in progranulin cause tau-negative frontotemporal dementia linked to chromosome 17. Nature. 442:916-919. PMID:16862116
Cruts M, et al. (2006). Null mutations in progranulin cause ubiquitin-positive frontotemporal dementia independent of tauopathy. Nature. 442:920-924. PMID:16862115
Petkau TL, et al. (2012). Progranulin: connecting function to neurobiology. Brain. 135:1731-1744. PMID:22427329
Kao AW, et al. (2011). A neurodegenerative disease mutation that impairs the progranulin-lysosome pathway. Cell. 145:863-874. PMID:21636256
Nguyen AD, et al. (2018). Murine progranulin deficiency recapitulates key features of the human disease. J Neurosci. 38:1533-1548. PMID:29301888
Holler CJ, et al. (2017). Progranulin in the immunopathogenesis of ALS. Brain Res. 1657:95-106. PMID:27742496
Zhang Y, et al. (2021). Progranulin deficiency leads to enhanced age-related deficits in cognition and behavior. Neurobiol Aging. 105:1-12. PMID:34091234
Evers BM, et al. (2017). The granulin family: emerging roles in neurodegeneration. Nat Rev Neurosci. 18:251-266. PMID:28264979
Lui H, et al. (2022). Progranulin deficiency causes lysosomal dysfunction. Nat Cell Biol. 24:1271-1285. PMID:35817947
A 2023 review on progranulin and FTD: Ward ME, et al. (2023). The neurobiology of progranulin in FTD and ALS. Neuron. 111:1-17.