Abstract
We have purified and characterized a 31-kDa protein named mapmodulin that binds to the microtubule-associated proteins (MAPs) MAP2, MAP4, and tau. Mapmodulin binds free MAPs in strong preference to microtubule-associated MAPs, and appears to do so via the MAP's tubulin-binding domain. Mapmodulin inhibits the initial rate of MAP2 binding to microtubules, a property that may allow mapmodulin to displace MAPs from the path of organelles translocating along microtubules. In support of this possibility, mapmodulin stimulates the microtubule- and dynein-dependent localization of Golgi complexes in semi-intact CHO cells. To our knowledge, mapmodulin represents the first example of a protein that can bind and potentially regulate multiple MAP proteins.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Amino Acid Sequence
-
Animals
-
Binding Sites
-
CHO Cells
-
Chromatography, Gel
-
Cricetinae
-
Cytosol
-
Dyneins / chemistry
-
Dyneins / physiology
-
Golgi Apparatus / physiology
-
Intracellular Membranes / physiology
-
Intracellular Signaling Peptides and Proteins
-
Kinetics
-
Microtubule-Associated Proteins / chemistry
-
Microtubule-Associated Proteins / isolation & purification
-
Microtubule-Associated Proteins / physiology*
-
Microtubules / physiology*
-
Microtubules / ultrastructure
-
Models, Structural
-
Nuclear Proteins
-
Peptide Fragments / chemistry
-
Protein Binding
-
Proteins / chemistry
-
Proteins / isolation & purification
-
Proteins / physiology*
-
RNA-Binding Proteins
Substances
-
ANP32A protein, human
-
Intracellular Signaling Peptides and Proteins
-
Microtubule-Associated Proteins
-
Nuclear Proteins
-
Peptide Fragments
-
Proteins
-
RNA-Binding Proteins
-
Dyneins