Abnormal Localization and Accumulation of FLT3-ITD, a Mutant Receptor Tyrosine Kinase Involved in Leukemogenesis
| Autor: | Martin F. Ryser, Gerhard Ehninger, Christian Thiede, Angela Jacobi, Sina Koch |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Histology
Golgi Apparatus Endoplasmic Reticulum Tropomyosin receptor kinase C Acute myeloid leukemia Receptor tyrosine kinase FLT3-ITD Subcellular localization Receptor tyrosine kinase Growth factor receptor Cell surface receptor Mutant protein Transduction Genetic Chlorocebus aethiops Animals Humans ddc:610 Secretory pathway Cell Nucleus Leukemia biology Endoplasmic reticulum Cell Membrane Cell biology Protein Structure Tertiary Protein Transport Retroviridae fms-Like Tyrosine Kinase 3 COS Cells subzelluläre Lokalisierung FLT3-ITD Rezeptortyrosinkinase akute myeloische Leukämie biology.protein Mutant Proteins Anatomy Platelet-derived growth factor receptor |
| Zdroj: | Cells Tissues Organs 2008;188:225–235, ISSN: 1422-6405 |
| Popis: | Aberrant subcellular localization of mutant transmembrane receptors is increasingly acknowledged as a possible mechanism for an altered signaling quality leading to transformation. There is evidence that mutated receptor tyrosine kinases of subclass III, for example the platelet-derived growth factor receptor (PDGFR) and KIT-protein, are aberrantly localized in human cancers. In order to further analyze this phenomenon, we investigated the localization of FLT3, a subclass III receptor tyrosine kinase frequently mutated in leukemia. By immunofluorescence staining and confocal laser scanning microscopy we found that in retrovirally transduced COS7 cells, wild type FLT3 receptor protein is localized primarily at the cell surface. In contrast, a mutant FLT3 receptor protein with an internal tandem duplication (ITD) accumulates in a perinuclear region and is not detectable at the plasma membrane. Surprisingly, and in contrast to previously published data, intracellular FLT3-ITD accumulation could neither be detected in the endoplasmic reticulum (ER) nor in the Golgi apparatus. Furthermore, transient overexpression per se leads to accumulation of wild type FLT3 receptor protein in the ER in addition to surface localization, probably due to inefficient intracellular transport by the overloaded sorting machinery of the secretory pathway. Based on our data and the immature glycosylation pattern of FLT3-ITD, we speculate that the mutant protein resides most probably in an unidentified compartment of the secretory pathway between the ER and the Golgi apparatus. Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich. |
| Databáze: | OpenAIRE |
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