The single transmembrane segment of gp210 is sufficient for sorting to the pore membrane domain of the nuclear envelope
| Autor: | Richard W. Wozniak, G Blobel |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1992 |
| Předmět: |
Nuclear Envelope
CD8 Antigens Recombinant Fusion Proteins DNA Mutational Analysis Molecular Sequence Data Fluorescent Antibody Technique Protein Sorting Signals Epitopes Mice Structure-Activity Relationship Animals Amino Acid Sequence Nuclear pore Nuclear protein Peptide sequence Mice Inbred BALB C Membrane Glycoproteins biology Base Sequence Nuclear Proteins Biological Transport Cell Biology Articles Fibroblasts Nuclear Pore Complex Proteins Membrane glycoproteins Transmembrane domain Biochemistry Cytoplasm Biophysics biology.protein Nucleoporin |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| Popis: | The glycoprotein gp210 is located in the "pore membrane," a specialized domain of the nuclear envelope to which the nuclear pore complex (NPC) is anchored. gp210 contains a large cisternal domain, a single transmembrane segment (TM), and a COOH-terminal, 58-amino acid residue cytoplasmic tail (CT) (Wozniak, R. W., E. Bartnik, and G. Blobel. 1989. J. Cell Biol. 108:2083-2092; Greber, U. F., A. Senior, and L. Gerace. 1990. EMBO (Eur. Mol. Biol. Organ.) J. 9:1495-1502). To locate determinants for sorting of gp210 to the pore membrane, we constructed various cDNAs coding for wild-type, mutant, and chimeric gp210, and monitored localization of the expressed protein in 3T3 cells by immunofluorescence microscopy using appropriate antibodies. The large cisternal domain of gp210 (95% of its mass) did not reveal any sorting determinants. Surprisingly, the TM of gp210 is sufficient for sorting to the pore membrane. The CT also contains a sorting determinant, but it is weaker than that of the TM. We propose specific lateral association of the transmembrane helices of two proteins to yield either a gp210 homodimer or a heterodimer of gp210 and another protein. The cytoplasmically oriented tails of these dimers may bind cooperatively to the adjacent NPCs. In addition, we demonstrate that gp210 co-localizes with cytoplasmically dispersed nucleoporins, suggesting a cytoplasmic association of these components. |
| Databáze: | OpenAIRE |
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