skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A gene encoding the major beta tubulin of the mitotic spindle in Physarum polycephalum plasmodia

Abstract

The multinucleate plasmodium of Physarum polycephalum is unusual among eucaryotic cells in that it uses tubulins only in mitotic-spindle microtubules; cytoskeletal, flagellar, and centriolar microtubules are absent in this cell type. The authors identified a ..beta..-tubulin cDNA clone, ..beta..105, which is shown to correspond to the transcript of the betC ..beta..-tubulin locus and to encode ..beta..2 tubulin, the ..beta.. tubulin expressed specifically in the plasmodium and used exclusively in the mitotic spindle. Physarum amoebae utilize tubulins in the cytoskeleton, centrioles, and flagella, in addition to the mitotic spindle. Sequence analysis shows that ..beta..2 tubulin is only 83% identical to the two ..beta.. tubulins expressed in amoebae. This compares with 70 to 83% identity between Physarum ..beta..2 tubulin and the ..beta.. tubulins of yeasts, fungi, alga, trypanosome, fruit fly, chicken, and mouse. On the other hand, Physarum ..beta..2 tubulin is no more similar to, for example, Aspergillus ..beta.. tubulins than it is to those of Drosophila melanogaster or mammals. Several eucaryotes express at least one widely diverged ..beta.. tubulin as well as one or more ..beta.. tubulins that conform more closely to a consensus ..beta..-tubulin sequence. The authors suggest that ..beta..-tubulins diverge more when their expression pattern is restricted, especially whenmore » this restriction results in their use in fewer functions. This divergence among ..beta.. tubulins could have resulted through neutral drift. For example, exclusive use of Physarum ..beta..2 tubulin in the spindle may have allowed more amino acid substitutions than would be functionally tolerable in the ..beta.. tubulins that are utilized in multiple microtubular organelles. Alternatively, restricted use of ..beta.. tubulins may allow positive selection to operate more freely to refine ..beta..-tubulin function.« less

Authors:
; ; ;
Publication Date:
Research Org.:
McArdle Lab. for Cancer Research, Univ. of Wisconsin, Madison, WI (US)
OSTI Identifier:
5113254
Resource Type:
Journal Article
Journal Name:
Mol. Cell. Biol.; (United States)
Additional Journal Information:
Journal Volume: 8:3
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; MICROTUBULES; STRUCTURE-ACTIVITY RELATIONSHIPS; PHYSARUM; CELL DIVISION; PROTEINS; AMINO ACID SEQUENCE; DNA BASE TRANSITIONS; GENETIC VARIABILITY; ALGAE; DNA-CLONING; DROSOPHILA; PHENOTYPE; TRYPANOSOMES; YEASTS; ANIMALS; ARTHROPODS; BIOLOGICAL VARIABILITY; CELL CONSTITUENTS; CLONING; DIPTERA; FLIES; FRUIT FLIES; FUNGI; INSECTS; INVERTEBRATES; MICROORGANISMS; MOLECULAR STRUCTURE; ORGANIC COMPOUNDS; PLANTS; 550400* - Genetics; 550700 - Microbiology; 550200 - Biochemistry

Citation Formats

Burland, T G, Paul, E C.A., Oetliker, M, and Dove, W F. A gene encoding the major beta tubulin of the mitotic spindle in Physarum polycephalum plasmodia. United States: N. p., 1988. Web. doi:10.1128/MCB.8.3.1275.
Burland, T G, Paul, E C.A., Oetliker, M, & Dove, W F. A gene encoding the major beta tubulin of the mitotic spindle in Physarum polycephalum plasmodia. United States. https://doi.org/10.1128/MCB.8.3.1275
Burland, T G, Paul, E C.A., Oetliker, M, and Dove, W F. 1988. "A gene encoding the major beta tubulin of the mitotic spindle in Physarum polycephalum plasmodia". United States. https://doi.org/10.1128/MCB.8.3.1275.
@article{osti_5113254,
title = {A gene encoding the major beta tubulin of the mitotic spindle in Physarum polycephalum plasmodia},
author = {Burland, T G and Paul, E C.A. and Oetliker, M and Dove, W F},
abstractNote = {The multinucleate plasmodium of Physarum polycephalum is unusual among eucaryotic cells in that it uses tubulins only in mitotic-spindle microtubules; cytoskeletal, flagellar, and centriolar microtubules are absent in this cell type. The authors identified a ..beta..-tubulin cDNA clone, ..beta..105, which is shown to correspond to the transcript of the betC ..beta..-tubulin locus and to encode ..beta..2 tubulin, the ..beta.. tubulin expressed specifically in the plasmodium and used exclusively in the mitotic spindle. Physarum amoebae utilize tubulins in the cytoskeleton, centrioles, and flagella, in addition to the mitotic spindle. Sequence analysis shows that ..beta..2 tubulin is only 83% identical to the two ..beta.. tubulins expressed in amoebae. This compares with 70 to 83% identity between Physarum ..beta..2 tubulin and the ..beta.. tubulins of yeasts, fungi, alga, trypanosome, fruit fly, chicken, and mouse. On the other hand, Physarum ..beta..2 tubulin is no more similar to, for example, Aspergillus ..beta.. tubulins than it is to those of Drosophila melanogaster or mammals. Several eucaryotes express at least one widely diverged ..beta.. tubulin as well as one or more ..beta.. tubulins that conform more closely to a consensus ..beta..-tubulin sequence. The authors suggest that ..beta..-tubulins diverge more when their expression pattern is restricted, especially when this restriction results in their use in fewer functions. This divergence among ..beta.. tubulins could have resulted through neutral drift. For example, exclusive use of Physarum ..beta..2 tubulin in the spindle may have allowed more amino acid substitutions than would be functionally tolerable in the ..beta.. tubulins that are utilized in multiple microtubular organelles. Alternatively, restricted use of ..beta.. tubulins may allow positive selection to operate more freely to refine ..beta..-tubulin function.},
doi = {10.1128/MCB.8.3.1275},
url = {https://www.osti.gov/biblio/5113254}, journal = {Mol. Cell. Biol.; (United States)},
number = ,
volume = 8:3,
place = {United States},
year = {Tue Mar 01 00:00:00 EST 1988},
month = {Tue Mar 01 00:00:00 EST 1988}
}