EMAP, an echinoderm microtubule-associated protein found in microtubule-ribosome complexes
- PMID: 9867489
- DOI: 10.1242/jcs.104.2.445
EMAP, an echinoderm microtubule-associated protein found in microtubule-ribosome complexes
Abstract
The major non-tubulin polypeptide found associated with microtubules purified from unfertilized sea urchin eggs by cycles of pH-dependent assembly has a Mr of 77,000. The 77,000 Mr polypeptide is heat- and acid-labile, and is antigenically distinct from the mammalian brain MAPs, MAP-2 and tau. Affinity-purified antiserum against the 77,000 Mr polypeptide was used to survey a variety of cells and tissues for the presence of antigenically related polypeptides. A cross-reacting polypeptide, ranging in Mr from 72,000 to 80,000, was found in microtubule preparations from a wide variety of echinoderms, including sea urchins, starfish and sand dollars. Indirect immunofluorescence showed that the polypetide was found in interphase as well as mitotic microtubule arrays. No cross-reacting material was detected in microtubules isolated from marine molluscs, mammalian brain or mouse B16 cultured cells. Because the 77,000 Mr MAP is abundant in echinoderms, we have called it EMAP for echinoderm microtubule-associated protein. Although the precise function of the EMAP is not known, our data suggest that the EMAP is involved in the attachment of ribosomes to microtubules. Large numbers of ribosomes are attached to the walls of EMAP-containing microtubules, but not EMAP-deficient microtubules. Removal of the EMAP from the microtubule by salt-extraction results in the release of ribosomes from the microtubule, indicating that the EMAP may form part or all of the long tapered stalk that connects these two organelles.
Similar articles
-
Purification of a WD repeat protein, EMAP, that promotes microtubule dynamics through an inhibition of rescue.J Biol Chem. 1998 Apr 10;273(15):9285-91. doi: 10.1074/jbc.273.15.9285. J Biol Chem. 1998. PMID: 9535922
-
EML proteins in microtubule regulation and human disease.Biochem Soc Trans. 2016 Oct 15;44(5):1281-1288. doi: 10.1042/BST20160125. Biochem Soc Trans. 2016. PMID: 27911710 Review.
-
The 77-kDa echinoderm microtubule-associated protein (EMAP) shares epitopes with the mammalian brain MAPs, MAP-2 and tau.Biochem Biophys Res Commun. 1998 Sep 18;250(2):502-5. doi: 10.1006/bbrc.1998.9271. Biochem Biophys Res Commun. 1998. PMID: 9753661
-
Cell cycle-dependent phosphorylation of the 77 kDa echinoderm microtubule-associated protein (EMAP) in vivo and association with the p34cdc2 kinase.J Cell Sci. 1996 Dec;109 ( Pt 12):2885-93. doi: 10.1242/jcs.109.12.2885. J Cell Sci. 1996. PMID: 9013336
-
Higher plant microtubule-associated proteins: in vitro functional assays.Biochimie. 1993;75(8):725-30. doi: 10.1016/0300-9084(93)90103-y. Biochimie. 1993. PMID: 8286444 Review.
Cited by
-
Molecular insights into intracellular RNA localization.Int Rev Cell Mol Biol. 2013;302:1-39. doi: 10.1016/B978-0-12-407699-0.00001-7. Int Rev Cell Mol Biol. 2013. PMID: 23351709 Free PMC article. Review.
-
Xenopus meiotic microtubule-associated interactome.PLoS One. 2010 Feb 17;5(2):e9248. doi: 10.1371/journal.pone.0009248. PLoS One. 2010. PMID: 20174651 Free PMC article.
-
Loss of dystrophin and the microtubule-binding protein ELP-1 causes progressive paralysis and death of adult C. elegans.Dev Dyn. 2009 Aug;238(8):1878-86. doi: 10.1002/dvdy.22007. Dev Dyn. 2009. PMID: 19582871 Free PMC article.
-
Molecular mechanisms that underpin EML4-ALK driven cancers and their response to targeted drugs.Cell Mol Life Sci. 2016 Mar;73(6):1209-24. doi: 10.1007/s00018-015-2117-6. Epub 2016 Jan 11. Cell Mol Life Sci. 2016. PMID: 26755435 Free PMC article. Review.
-
The Transcriptional Roles of ALK Fusion Proteins in Tumorigenesis.Cancers (Basel). 2019 Jul 30;11(8):1074. doi: 10.3390/cancers11081074. Cancers (Basel). 2019. PMID: 31366041 Free PMC article. Review.
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Miscellaneous