Phosphorylation of the medium chain subunit of the AP‐2 adaptor complex does not influence its interaction with the tyrosine based internalisation motif of TGN38

FEBS Letters

Crump, Colin M.¹  Banting, George¹ 

[1] Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK

关键词: Clathrin;    Adaptor;    Phosphorylation;    Tyrosine motif;    Dynamin;    TGN;    trans-Golgi network;    AP;    adaptor protein;    CKII;    casein kinase II;    PMSF;    phenylmethylsulphonyl fluoride;    PVDF;    polyvinylidene difluoride;    IPTG;    isopropyl-β-d-thiogalactopyranoside;    TRX;    thioredoxin;   

DOI  :  10.1016/S0014-5793(99)00066-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Tyrosine based motifs conforming to the consensus YXXΦ (where Φ represents a bulky hydrophobic residue) have been shown to interact with the medium chain subunit of clathrin adaptor complexes. These medium chains are targets for phosphorylation by a kinase activity associated with clathrin coated vesicles. We have used the clathrin coated vesicle associated kinase activity to specifically phosphorylate a soluble recombinant fusion protein of μ2, the medium chain subunit of the plasma membrane associated adaptor protein complex AP-2. We have tested whether this phosphorylation has any effect on the interaction of μ2 with the tyrosine based motif containing protein, TGN38, that has previously been shown to interact with μ2. Phosphorylation of μ2 was shown to have no significant effect on the in vitro interaction of μ2 with the cytosolic domain of TGN38, indicating that reversible phosphorylation of μ2 does not play a role in regulating its direct interaction with tyrosine based internalisation motifs. In addition, although a casein kinase II-like activity has been shown to be associated with clathrin coated vesicles, we show that μ2 is not phosphorylated by casein kinase II implying that another kinase activity is present in clathrin coated vesicles. Furthermore the kinase activity associated with clathrin coated vesicles was shown to be capable of phosphorylating dynamin 1. Phosphorylation of dynamin 1 has previously been shown to regulate its interaction with other proteins involved in clathrin mediated endocytosis.

【 授权许可】

Unknown