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Differential Endosomal Sorting of a Novel P2Y 12 Purinoreceptor Mutant
Author(s) -
Cunningham Margaret R.,
Nisar Shaista P.,
Cooke Alexandra E.,
Emery Elizabeth D.,
Mundell Stuart J.
Publication year - 2013
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/tra.12054
Subject(s) - endosome , retromer , biology , internalization , microbiology and biotechnology , p2y receptor , endocytic cycle , receptor , purinergic receptor , endocytosis , biochemistry , intracellular
P2Y 12 receptor internalization and recycling play an essential role in ADP ‐induced platelet activation. Recently, we identified a patient with a mild bleeding disorder carrying a heterozygous mutation of P2Y 12 ( P341A ) whose P2Y 12 receptor recycling was significantly compromised. Using human cell line models, we identified key proteins regulating wild‐type ( WT ) P2Y 12 recycling and investigated P2Y 12 ‐P341A receptor traffic. Treatment with ADP resulted in delayed Rab5‐dependent internalization of P341A when compared with WT P2Y 12 . While WT P2Y 12 rapidly recycled back to the membrane via Rab4 and Rab11 recycling pathways, limited P341A recycling was observed, which relied upon Rab11 activity. Although minimal receptor degradation was evident, P341A was localized in Rab7‐positive endosomes with considerable agonist‐dependent accumulation in the trans ‐Golgi network ( TGN ). Rab7 activity is known to facilitate recruitment of retromer complex proteins to endosomes to transport cargo to the TGN . Here, we identified that P341A colocalized with Vps26; depletion of which blocked limited recycling and promoted receptor degradation. This study has identified key points of divergence in the endocytic traffic of P341A versus WT‐P2Y 12 . Given that these pathways are retained in human platelets, this research helps define the molecular mechanisms regulating P2Y 12 receptor traffic and explain the compromised receptor function in the platelets of the P2Y 12 ‐P341A ‐expressing patient.