Dynamitin Mutagenesis Reveals Protein-Protein Interactions Important for Dynactin Structure

Dynamitin Mutagenesis Reveals Protein-Protein Interactions Important for Dynactin Structure

Dynactin is a highly conserved, multiprotein complex that works in conjunction with microtubule-based motors to power a variety of intracellular motile events. Dynamitin (p50) is a core element of dynactin structure. In the present study, we use targeted mutagenesis to evaluate how dynamitin's...

Full description

Saved in:
Bibliographic Details
Published in:Traffic (Copenhagen, Denmark) Vol. 9; no. 4; pp. 481 - 491
Main Authors: Maier, Kerstin C, Godfrey, Jamie E, Echeverri, Christophe J, Cheong, Frances K.Y, Schroer, Trina A
Format: Journal Article
Language:English
Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-04-2008
Blackwell Publishing Ltd
Subjects:
Animals
Cattle
Chickens
dynactin
Dynactin Complex
dynein
Humans
microtubule
Microtubule-Associated Proteins - chemistry
Microtubule-Associated Proteins - genetics
Microtubule-Associated Proteins - metabolism
motility
motor
Mutagenesis
Protein Conformation
Protein Subunits - genetics
Protein Subunits - metabolism
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Dynactin is a highly conserved, multiprotein complex that works in conjunction with microtubule-based motors to power a variety of intracellular motile events. Dynamitin (p50) is a core element of dynactin structure. In the present study, we use targeted mutagenesis to evaluate how dynamitin's different structural domains contribute to its ability to self-associate, interact with dynactin and assemble into a complex with its close binding partner, p24. We show that these interactions involve three distinct structural elements: (i) a previously unidentified dimerization motif in the N-terminal 100 amino acids, (ii) an α-helical motif spanning aa 106-162 and (iii) the C-terminal half of the molecule (aa 213-406), which is predicted to fold into an antiparallel α-helix bundle. The N-terminal half of dynamitin by itself is sufficient to disrupt dynactin, although very high concentrations are required. The ability of mutations in dynamitin's interaction domains to disrupt dynactin in vitro was found to correlate with their inhibitory effects when expressed in cells. We determined that the dynactin subunit, p24, governs dynamitin oligomerization by binding dynamitin along its length. This suppresses aberrant multimerization and drives formation of a protein complex that is identical to the native dynactin shoulder.
Bibliography:http://dx.doi.org/10.1111/j.1600-0854.2008.00702.x
ISSN:1398-9219
1600-0854
DOI:10.1111/j.1600-0854.2008.00702.x