Identification of G-protein coupled receptor kinase 2 in paired helical filaments and neurofibrillary tangles

Makio Takahashi, Hirotake Uchikado, Domenico Caprotti, Karen M. Weidenheim, Dennis W. Dickson, Hanna Ksiezak-Reding, Giulio M. Pasinetti

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


G-protein coupled receptor kinases (GRKs) constitute a serine/threonine kinase family playing a major role in agonist-induced phosphorylation and desensitization of G-protein coupled receptors. Recently, GRK2 and GRK5 have been demonstrated to phosphorylate α-synuclein (Ser129) and other synuclein isoforms. We studied colocalization of GRK2, GRK5, α-synuclein, and tau in neurodegenerative disorders characterized by fibrillary tau inclusions and/or α-synuclein-enriched Lewy bodies. We found that Lewy bodies were negative for both GRK2 and GRK5 in Lewy body disease (LBD) and LBD mixed with Alzheimer disease (AD + LBD). Instead, GRK2 but not GRK5 colocalized with 40% to 50% of neurofibrillary tangles in AD + LBD and AD brains. In disorders with less prominent α-synucleinopathy, neuronal and glial fibrillary tau deposits known to contain distinct subsets of tau isoforms were also positive for GRK2. These deposits included tufted astrocytes and coiled bodies in progressive supranuclear palsy, astrocytic plaques in corticobasal degeneration, and Pick bodies in Pick disease. In addition, paired helical filaments isolated from AD and AD + LBD brains were found to immunogold-label for GRK2, suggesting that GRK2 could be a potential tau kinase associated with fibrillary tau. Our studies indicate that GRK2 is a novel component of neuronal and glial fibrillary tau deposits with no preference in tau isoform binding. GRK2 may play a role in hyperphosphorylation of tau in tauopathies.

Original languageEnglish (US)
Pages (from-to)1157-1169
Number of pages13
JournalJournal of Neuropathology and Experimental Neurology
Issue number12
StatePublished - Dec 2006


  • Alzheimer disease
  • Corticobasal degeneration
  • Lewy body disease
  • Pick disease
  • Progressive supranuclear palsy
  • Tau

ASJC Scopus subject areas

  • General Medicine


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