Cloning and Expression of Gamma-adaptin, a Component of Clathrin-coated Vesicles Associated with the Golgi Apparatus
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Adaptins are the major components of adaptors, the protein complexes that link clathrin to transmembrane proteins (e.g., receptors) in coated pits and vesicles. The plasma membrane adaptor contains an alpha-adaptin subunit and a beta-adaptin subunit, while the Golgi adaptor contains a gamma-adaptin subunit and a beta'-adaptin subunit. A partial cDNA clone encoding gamma-adaptin was isolated from a bovine brain expression library by screening with antibodies, and was used to obtain a cDNA clone from a mouse brain library containing the full coding sequence. The identity of the clones was confirmed by protein sequencing. 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. Weaker homology was seen between gamma- and beta-adaptins. Like both alpha- and beta-adaptins, gamma-adaptin has a proline and glycine-rich hinge region, dividing it into NH2- and COOH-terminal domains. A chimeric gamma-adaptin was constructed from the mouse and bovine cDNAs and transfected into Rat 1 fibroblasts. Immunofluorescence microscopy was carried out using an mAb which recognizes an epitope present on the chimera but not found on the rodent protein. The construct was found to have a distribution typical of endogenous gamma-adaptin. Using this transfection system, it should now be possible to exchange domains between alpha- and gamma-adaptins, to try to find out how adaptors are targeted to the appropriate membrane compartment of the cell, and how they recruit the appropriate receptors into the coated vesicle.
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Hooy R, Iwamoto Y, Tudorica D, Ren X, Hurley J Sci Adv. 2022; 8(42):eadd3914.
PMID: 36269825 PMC: 9586487. DOI: 10.1126/sciadv.add3914.
Kot M, Mazurkiewicz E, Wiktor M, Wiertelak W, Mazur A, Rahalevich A Cells. 2022; 11(15).
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Li S, Lisanti M, Puszkin S Bioquim Patol Clin. 2019; 62(1):5-17.
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Wensel T, Zhang Z, Anastassov I, Gilliam J, He F, Schmid M Prog Retin Eye Res. 2016; 55:32-51.
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