Stathmin family proteins display specific molecular and tubulin binding properties.
Stathmin family phosphoproteins (stathmin, SCG10, SCLIP, and RB3/RB3'/RB3") are involved in signal transduction and regulation of microtubule dynamics. With the exception of stathmin, they are expressed exclusively in the nervous system, where they display different spatio-temporal and functional regulations and hence play at least partially distinct and possibly complementary roles in relation to the control of development, plasticity, and neuronal activities. At the molecular level, each possesses a specific "stathmin-like domain" and, with the exception of stathmin, various combinations of N-terminal extensions involved in their association with intracellular membrane compartments. We show here that each stathmin-like domain also displays specific biochemical and tubulin interaction properties. They are all able to sequester two alpha/beta tubulin heterodimers as revealed by their inhibitory action on tubulin polymerization and by gel filtration. However, they differ in the stabilities of the complexes formed as well as in their interaction kinetics with tubulin followed by surface plasmon resonance as follows: strong stability and slow kinetics for RB3; medium for SCG10, SCLIP, and stathmin; and weak stability and rapid kinetics for RB3'. These results suggest that the fine-tuning of their stathmin-like domains contributes to the specific functional roles of stathmin family proteins in the regulation of microtubule dynamics within the various cell types and subcellular compartments of the developing or mature nervous system.
INSERM U440, Institut du Fer à Moulin, 17 Rue du Fer à Moulin and CNRS, UMR 7637, Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, 10 Rue Vauquelin, 75005 Paris, France.
E
E
Charbaut
P A
PA
Curmi
S
S
Ozon
S
S
Lachkar
V
V
Redeker
A
A
Sobel
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008565:Membrane Proteins; D051379:Mice; D008868:Microtubule Proteins; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000737:chemistry / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry* / Q000378:metabolism*; D017433:Protein Structure, Secondary; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D050777:Stathmin; D020349:Surface Plasmon Resonance; D014404:Tubulin / Q000378:metabolism*
D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008868:Microtubule Proteins; D009414:Nerve Growth Factors; D010750:Phosphoproteins; D011994:Recombinant Proteins; D050777:Stathmin; C493994:Stmn1 protein, mouse; C512849:Stmn2 protein, mouse; C512848:Stmn2 protein, rat; C491793:Stmn3 protein, mouse; C491792:Stmn3 protein, rat; C491794:Stmn4 protein, mouse; C112286:Stmn4 protein, rat; D014404:Tubulin