Identification and characterization of novel clathrin adaptor-related proteins

J Biol Chem. 1998 Sep 18;273(38):24693-700. doi: 10.1074/jbc.273.38.24693.

Abstract

We have identified a human approximately 87-kDa protein, designated as gamma2-adaptin, that is similar to gamma-adaptin (called gamma1-adaptin in this paper), a large chain of the AP-1 clathrin-associated adaptor complex, not only in the primary structure (60% amino acid identity) but also in the domain organization. Northern blot analysis has shown that its mRNA is expressed in a variety of tissues. Analysis using a yeast two-hybrid system has revealed that, similarly to gamma1-adaptin, gamma2-adaptin is capable of interacting not only with the sigma1 chain (called as sigma1A in this paper), the small chain of the AP-1 complex, but also with a novel sigma1-like protein, designated as sigma1B, which shows an 87% amino acid identity to sigma1A; and that, unlike gamma1-adaptin, it is unable to interact with beta1-adaptin, another large chain of the AP-1 complex. Immunofluorescence microscopy analysis has revealed that gamma2-adaptin is localized to paranuclear vesicular structures that are not superimposed on structures containing gamma1-adaptin. Furthermore, unlike gamma1-adaptin, gamma2-adaptin is recruited onto membranes in the presence of a fungal antibiotic, brefeldin A. These data suggest that gamma2-adaptin constitute a novel adaptor-related complex that participates in a transport step different from that of AP-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Protein Complex 1*
  • Adaptor Protein Complex 2*
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Protein Complex gamma Subunits
  • Adaptor Protein Complex sigma Subunits*
  • Adaptor Proteins, Vesicular Transport
  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Cell Line
  • Clathrin / chemistry
  • Cloning, Molecular
  • DNA Primers
  • Humans
  • Membrane Proteins / biosynthesis*
  • Membrane Proteins / chemistry
  • Molecular Sequence Data
  • Organ Specificity
  • Polymerase Chain Reaction
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transcription Factor AP-1 / chemistry
  • Transcription Factor AP-1 / metabolism*
  • Transcription, Genetic*
  • Transfection
  • Tumor Cells, Cultured

Substances

  • AP1S1 protein, human
  • AP2S1 protein, human
  • APS1 protein, S cerevisiae
  • Adaptor Protein Complex 1
  • Adaptor Protein Complex 2
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Protein Complex gamma Subunits
  • Adaptor Protein Complex sigma Subunits
  • Adaptor Proteins, Vesicular Transport
  • Clathrin
  • DNA Primers
  • Membrane Proteins
  • RNA, Messenger
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factor AP-1
  • adaptor protein complex 1, sigma 1 subunit

Associated data

  • GENBANK/AB015317
  • GENBANK/AB015318
  • GENBANK/AB015319
  • GENBANK/AB015320