Golgi Distribution of Lyn to Caveolin- and Giantin-Positive cis-Golgi Membranes and the Caveolin-Negative, TGN46-Positive trans-Golgi Network.
Src-family tyrosine kinases, classified as cytosolic enzymes, have crucial roles in regulating cell proliferation, differentiation, migration and cell-shape changes. Newly synthesized Lyn, a member of Src-family kinases, is biosynthetically accumulated at the cytoplasmic face of caveolin-containing Golgi membranes via posttranslational lipid modifications and then transported to the plasma membrane. However, the precise intra-Golgi localization of Lyn remains elusive. By means of a 19°C block-release technique and short-term brefeldin A treatment, we show here that the distribution of Lyn is not monotonously spread within the Golgi but selectively intensified in two distinct membrane compartments: giantin- and caveolin-positive membranes and trans-Golgi network protein (TGN)46-positive but caveolin-negative membranes. Furthermore, Lyn exits the Golgi from the caveolin-positive cis-Golgi cisternae or the caveolin-negative trans-Golgi network. These results suggest that Lyn moves apart from caveolin, a secretory protein, within the Golgi during Lyn's trafficking to the plasma membrane.
['Okamoto|Aya|A|', 'Morinaga|Takao|T|', 'Yamaguchi|Noritaka|N|', 'Yamaguchi|Naoto|N|']
D000818:Animals D019556:COS Cells D022461:Caveolins D002522:Chlorocebus aethiops D006056:Golgi Apparatus D000077614:Golgi Matrix Proteins D007425:Intracellular Membranes D008562:Membrane Glycoproteins D008565:Membrane Proteins D021381:Protein Transport D019061:src-Family Kinases D021601:trans-Golgi Network
Golgi Lyn caveolin trafficking giantin trans-Golgi network protein (TGN)46