Nucleocytoplasmic shuttling of endocytic proteins.
Many cellular processes rely on the ordered assembly of macromolecular structures. Here, we uncover an unexpected link between two such processes, endocytosis and transcription. Many endocytic proteins, including eps15, epsin1, the clathrin assembly lymphoid myeloid leukemia (CALM), and alpha-adaptin, accumulate in the nucleus when nuclear export is inhibited. Endocytosis and nucleocytoplasmic shuttling of endocytic proteins are apparently independent processes, since inhibition of endocytosis did not appreciably alter nuclear translocation of endocytic proteins, and blockade of nuclear export did not change the initial rate of endocytosis. In the nucleus, eps15 and CALM acted as positive modulators of transcription in a GAL4-based transactivation assay, thus raising the intriguing possibility that some endocytic proteins play a direct or indirect role in transcriptional regulation.
Vecchi
M
M
Department of Experimental Oncology, European Institute of Oncology, 20141 Milan, Italy.
Polo
S
S
Poupon
V
V
van de Loo
J W
JW
Benmerah
A
A
Di Fiore
P P
PP
D021581:Active Transport, Cell Nucleus / Q000502:physiology; D033965:Adaptor Protein Complex alpha Subunits; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000378:metabolism*; D004268:DNA-Binding Proteins; D004705:Endocytosis / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000378:metabolism; D034041:Monomeric Clathrin Assembly Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology; D015533:Transcriptional Activation / Q000502:physiology; D033921:Vesicular Transport Proteins
D033965:Adaptor Protein Complex alpha Subunits; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C486206:EPS15 protein, human; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D034041:Monomeric Clathrin Assembly Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; C439003:PICALM protein, human; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D033921:Vesicular Transport Proteins; C114154:epsin