Disease relevance of Dynlt1

• A dynein light chain of sea urchin sperm flagella is a homolog of mouse Tctex 1, which is encoded by a gene of the t complex sterility locus [1].
• The chromosomal location and pattern of expression of tctex-1 make it a candidate for involvement in male sterility [2].
• Expression of tctex-1 mRNA and protein was observed in all lymphoma lines analyzed, and immunofluorescence confocal microscopy localized the protein to the perinuclear region [3].

High impact information on Dynlt1

• tctex-1: a candidate gene family for a mouse t complex sterility locus [2].
• The aberrant expression of tctex-1 is solely dependent on the t haplotype genes and occurs only in germ cells [2].
• We have isolated a multigene family, tctex-1, by screening a testicular cell cDNA library with two reciprocally subtracted testicular cDNA probes [2].
• The tctex-1 gene family produces an abundant, virtually germ cell-specific transcript that is 8-fold overexpressed in t homozygotes [2].
• Genetic and biochemical dissection of the Chlamydomonas flagellum reveal that Tctex1 is a previously undescribed component of inner dynein arm I1 [4].

Biological context of Dynlt1

• The cytoplasmic dynein light chain Tctex1 is a candidate for one of the distorter products involved in the non-Mendelian transmission of mouse t haplotypes [4].
• The data showed that Tctex-1 adopts a structure remarkably similar to that of the 8-kDa light chain of the motor complex (DLC8), although the two light chains share no amino acid sequence homology [5].
• The Tctex-1 binding site on DIC was mapped to a 19-residue fragment immediately following the second alternative splicing site of DIC [5].
• The Tctex1/Tctex2 class of dynein light chains. Dimerization, differential expression, and interaction with the LC8 protein family [6].
• Combined with the recent identification of Tctex-1 (another distorter candidate) as a light chain of cytoplasmic dynein, these results lead to a biochemical model for how differential defects in spermiogenesis that result in the phenomenon of meiotic drive might be generated in wild-type vs t-bearing sperm [7].

Anatomical context of Dynlt1

• Here, we demonstrate that Tctex1 is not only a cytoplasmic dynein component, but is also present both in mouse sperm and Chlamydomonas flagella [4].
• The minus-ended microtubule motor cytoplasmic dynein contains a number of low molecular weight light chains including the 14-kDa Tctex-1 [5].
• We find that Tctex-1 protein is present in sperm tails and oocytes and that it is present at equal levels in wild-type and t-haplotype testis [8].
• Tctex-1 binding required the first 19 amino acids of Fyn and integrity of two lysine residues within this sequence that were previously shown to be important for Fyn interactions with the immunoreceptor tyrosine-based activation motifs (ITAMs) of lymphocyte Ag receptors [3].
• Interestingly, four Tctex genes show differences in the amount of transcript between wild-type and t-mutant testes [9].

Associations of Dynlt1 with chemical compounds

• We further demonstrated that Tctex-1 binds directly to the intermediate chain (DIC) of dynein [5].

Physical interactions of Dynlt1

• We utilized yeast two-hybrid cloning to identify the product of the tctex-1 gene as a protein that specifically interacts with Fyn, but not with other Src family kinases [3].

Regulatory relationships of Dynlt1

• These genes were named t-complex testis-expressed (Tctex) genes [9].

Other interactions of Dynlt1

• Structure of Tctex-1 and its interaction with cytoplasmic dynein intermediate chain [5].
• The Tctex1/Tctex2 family of dynein light chains associates with the intermediate chains at the base of the soluble dynein particle [6].
• Identification of the t complex-encoded cytoplasmic dynein light chain tctex1 in inner arm I1 supports the involvement of flagellar dyneins in meiotic drive [4].
• YACs mapped with respect to deletion breakpoints localize tcs1 to a 1.1-Mb interval flanked by D17Aus9 and Tctex1 [10].

Analytical, diagnostic and therapeutic context of Dynlt1

• Gel filtration chromatography and native gel electrophoresis indicate that recombinant Chlamydomonas flagellar Tctex1 exists as a dimer in solution [6].
• Immunofluorescence analysis was consistent with the tissue-specific distribution of these proteins and revealed that both rp3 and Tctex1 are present in multiple perinuclear punctate particles [11].

References