A tyrosine-based signal plays a critical role in the targeting and function of adenovirus RIDalpha protein.
Early region 3 genes of human adenoviruses contribute to the virus life cycle by altering the trafficking of cellular proteins involved in adaptive immunity and inflammatory responses. The ability of early region 3 genes to target specific molecules suggests that they could be used to curtail pathological processes associated with these molecules and treat human disease. However, this approach requires genetic dissection of the multiple functions attributed to early region 3 genes. The purpose of this study was to determine the role of targeting on the ability of the early region 3-encoded protein RIDalpha to downregulate the EGF receptor. A fusion protein between the RIDalpha cytoplasmic tail and glutathione S-transferase was used to isolate clathrin-associated adaptor 1 and adaptor 2 protein complexes from mammalian cells. Deletion and site-directed mutagenesis studies showed that residues 71-AYLRH of RIDalpha are necessary for in vitro binding to both adaptor complexes and that Tyr72 has an important role in these interactions. In addition, RIDalpha containing a Y72A point mutation accumulates in the trans-Golgi network and fails to downregulate the EGF receptor when it is introduced into mammalian cells as a transgene. Altogether, our data suggest a model where RIDalpha is trafficked directly from the trans-Golgi network to an endosomal compartment, where it intercepts EGF receptors undergoing constitutive recycling to the plasma membrane and redirects them to lysosomes.
Cianciola
Nicholas L
NL
Department of Physiology and Biophysics, Case Western Reserve University Cancer Center, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106-4970, USA.
Crooks
Denise
D
Shah
Ankur H
AH
Carlin
Cathleen
C
D033961:Adaptor Protein Complex 1 / Q000378:metabolism; D033962:Adaptor Protein Complex 2 / Q000378:metabolism; D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D015536:Down-Regulation; D011992:Endosomes / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D005982:Glutathione Transferase / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D017354:Point Mutation; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014443:Tyrosine / Q000737:chemistry / Q000235:genetics; D014764:Viral Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism*
D033961:Adaptor Protein Complex 1; D033962:Adaptor Protein Complex 2; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D014443:Tyrosine; D005982:Glutathione Transferase; D066246:ErbB Receptors