High impact information on Ap1g1

• Polarized epithelial cells are the only cells of micro1A-adaptin-deficient embryos that show gamma-adaptin binding to membranes, indicating the formation of an epithelial specific AP-1B complex and demonstrating the absence of additional mu1A homologs [1].
• Using a polyclonal antibody against the mouse gamma-adaptin, we have now examined the steady state distribution of AP-1 after subcellular fractionation of mouse fibroblasts lacking both MPRs or reexpressing physiological levels of either MPR [2].
• The deduced amino acid sequence of gamma-adaptin was found to be homologous to that of alpha-adaptin, with several stretches of identical amino acids or conservative substitutions in the first approximately 70 kD, and 25% identity overall [3].
• Like both alpha- and beta-adaptins, gamma-adaptin has a proline and glycine-rich hinge region, dividing it into NH2- and COOH-terminal domains [3].
• Cloning and expression of gamma-adaptin, a component of clathrin-coated vesicles associated with the Golgi apparatus [3].

Biological context of Ap1g1

• We generated mutants of the gamma-adaptin subunit of AP-1 in mice to investigate its role in post-Golgi vesicle transport and sorting processes. gamma-Adaptin-deficient embryos develop until day 3.5 post coitus and die during the prenidation period, revealing that AP-1 is essential for viability [4].
• The GGAs (Golgi-localizing, gamma-adaptin ear homology domain, ARF-binding) are a multidomain family of proteins implicated in protein trafficking between the Golgi and endosomes [5].

Anatomical context of Ap1g1

• A chimeric gamma-adaptin was constructed from the mouse and bovine cDNAs and transfected into Rat 1 fibroblasts [3].
• On the other hand, gamma-adaptin, an adaptor molecule of a complex involved in trafficking from the Golgi to lysosomes, was expressed in cytoplasmic vesicles only in pachytene and Cap-phase spermatids (steps 1-5) [6].
• Myoblasts stained with C172 revealed a polarized distribution of vesicles distinct from that observed when cells are stained with gamma adaptin antibody which is known to localize to trans Golgi network [7].

Associations of Ap1g1 with chemical compounds

• Using immunoelectron microscopy, we have shown that GLUT-4 is localized to intracellular vesicles containing the Golgi-derived gamma-adaptin subunit of AP-1 and that this localization is enhanced when Ser-488 is mutated to alanine [8].

References