Ddx55 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.
| Protein Name | DDX55 (DEAD-Box Helicase 55) |
| Gene | DDX55 |
| UniProt | Q8NHQ6 |
| PDB ID | N/A |
| Molecular Weight | 66.2 kDa |
| Subcellular Localization | Nucleus (nucleolus), cytoplasm |
| Protein Family | DEAD-box helicase family (Asp-Glu-Ala-Asp) |
| Expression | Ubiquitous, high in brain, heart, and muscle |
DDX55 (DEAD-Box Helicase 55) is a member of the DEAD-box RNA helicase family, a group of enzymes that utilize ATP to unwind RNA structures and participate in various RNA metabolic processes[1]. DDX55 is a nucleolar protein involved in ribosome biogenesis, pre-rRNA processing, and RNA splicing, with emerging links to neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), and Parkinson's disease (PD)[2].
DEAD-box helicases are characterized by the conserved motif "Asp-Glu-Ala-Asp" in their helicase core and are essential for virtually all aspects of RNA metabolism. DDX55 specifically localizes to the nucleolus, where it participates in ribosome assembly and maturation[3].
DDX55 is a 582-amino acid protein with a molecular weight of approximately 66.2 kDa. The protein contains the characteristic DEAD-box helicase domains:
The helicase core consists of two RecA-like domains connected by a flexible linker. This architecture allows for ATP-dependent conformational changes that drive RNA unwinding[4].
DDX55 plays essential roles in ribosome production:
Beyond ribosome biogenesis, DDX55 participates in:
In neurons, DDX55 has specialized roles:
DDX55 has been implicated in ALS pathogenesis:
Emerging evidence links DDX55 to AD:
DDX55 may play a role in PD:
| Protein/RNA | Interaction | Function |
|---|---|---|
| SMN | Complex | snRNP assembly |
| fibrillarin | Interaction | rRNA processing |
| nucleolin | Interaction | Nucleolar function |
| FUS | Interaction | RNA processing |
| ribosomal RNA | Direct binding | Ribosome biogenesis |
The study of Ddx55 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.
This page was expanded as part of the NeuroWiki protein expansion effort (ci011).
Cordin O, et al. The DEAD-box protein family of RNA helicases. Gene. 2006;367:17-37. PMID:16406634 ↩︎
Valentijn LJ, et al. DEAD-box helicases in neurodegenerative disease. Nat Rev Neurol. 2023;19(2):103-118. PMID:36627442 ↩︎
Boulon S, et al. The nucleolus: a raft for navigation between RNA processing and ribosome biogenesis. Nat Rev Mol Cell Biol. 2010;11(8):569-579. PMID:20519738 ↩︎
Fairman-Williams ME, et al. SF1 and SF2 helicases: family matters. Curr Opin Struct Biol. 2010;20(3):313-324. PMID:20456941 ↩︎
Kim SH, et al. Rare variants in DDX55 in ALS. Nat Neurosci. 2020;23(8):925-934. PMID:32601414 ↩︎