The mouse t-complex-encoded protein Tctex-1 is a light chain of brain cytoplasmic dynein.
Mammalian brain cytoplasmic dynein contains three light chains of Mr = 8,000, 14,000, and 22,000 (King, S. M., Barbarese, E., Dillman, J. F., III, Patel-King, R. S., Carson, J. H., and Pfister, K. K. (1996) J. Biol. Chem. 271, 19358-19366). Peptide sequence data (16/16 residues correct) implicate the Mr = 14,000 polypeptide as Tctex-1, a protein encoded within the mouse t-complex. Tctex-1 cosediments with microtubules and is eluted with ATP or salt but not with GTP as expected for a dynein subunit. The ATP-eluted protein precisely cosediments with known cytoplasmic dynein proteins in sucrose density gradients. Tctex-1 also is immunoprecipitated from brain and other tissue homogenates by a monoclonal antibody raised against the 74-kDa cytoplasmic dynein intermediate chain. Quantitative densitometry indicates that Tctex-1 is a stoichiometric component of the dynein complex. As Tctex-1 is a candidate for involvement in the transmission ratio distortion (meiotic drive) of mouse t-haplotypes, these results suggest that cytoplasmic dynein dysfunction may play an important role in non-mendelian chromosome segregation.
King
S M
SM
Department of Biochemistry, University of Connecticut Health Center, Farmington, Connecticut 06032-3305, USA. king@panda.uchc.edu
Dillman
J F
JF
Benashski
S E
SE
Lye
R J
RJ
Patel-King
R S
RS
Pfister
K K
KK
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000737:chemistry; D002499:Centrifugation, Density Gradient; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins / Q000737:chemistry*; D004398:Dyneins / Q000737:chemistry*; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins / Q000737:chemistry; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016415:Sequence Alignment
D001426:Bacterial Proteins; D002352:Carrier Proteins; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins; D004398:Dyneins