Disease relevance of alphaTub84B

• The dominant male sterility of the revertant alleles is suppressed if the flies are also heterozygous for B2tn, for a deficiency of alpha 1t, or for the haync2 allele [1].
• A lambda phage clone containing alpha 1-tubulin specific sequences was isolated from a genomic DNA library of Drosophila auraria and its restriction endonuclease pattern is presented [2].

Psychiatry related information on alphaTub84B

• The polarity of kinesin's motor activity can be reversed by MT disassembly and interactions between a motor and a MT end can either slow or speed the rate of tubulin depolymerization [3].

High impact information on alphaTub84B

• We define 3' apical localization signals within the even-skipped, fushi tarazu, and hairy pair-rule segmentation genes and the alpha 1-tubulin and bicoid genes [4].
• Regulation of tubulin gene expression during embryogenesis in Drosophila melanogaster [5].
• Three of them are present only once in the haploid genome; the other, T alpha 1, is present in either one or two copies [6].
• DNA hybridization studies demonstrated, however, that three of them have extensive sequence homology with each other and slight homology with the fourth, T alpha 4 [6].
• Both the polymerization and depolymerization of tubulin have been shown to do work in vitro, but the biochemical complexity of objects moved, such as chromosomes, has complicated the identification of proteins that couple MT dynamics with motility [3].

Biological context of alphaTub84B

• We tested the ability of the developmentally regulated alpha 85E-tubulin isoform to replace alpha 84B in spermatogenesis [7].
• Southern blots revealed a total of five to seven alpha-tubulin genes encoded in the G. lateralis genome [8].
• Four alpha-tubulin isoforms recovered from a cDNA library from regenerating limb buds of the Bermuda land crab Gecarcinus lateralis have been characterized [8].
• When compared with other species; nucleotide sequences of all four clones showed highest homology to alpha-tubulin genes of an insect (Drosophila melanogaster), while their predicted amino acid sequences were most highly homologous to an alpha-tubulin of a mammal (Rattus norvegicus) [8].
• Here we use Drosophila melanogaster S2 cells expressing alpha-tubulin tagged with green fluorescent protein, RNA interference, laser microsurgery and photobleaching to show that the kinetochore protein MAST/Orbit - the single CLASP orthologue in Drosophila - is an essential component for microtubule subunit incorporation into fluxing K-fibres [9].

Anatomical context of alphaTub84B

• We used transgenic analysis in Drosophila to compare the ability of two structurally similar alpha-tubulin isoforms to support microtubule assembly in vivo [7].
• In spermatogenesis, all microtubule functions in the postmitotic male germ cells are carried out by a single tubulin heterodimer composed of the major Drosophila alpha-84B tubulin isoform and the testis-specific beta 2-tubulin isoform [7].
• Although alpha4-tubulin comprises only about one-fifth of the alpha-tubulin pool in every Drosophila egg, in the absence of alpha4-tubulin - in eggs of the kavar(0)/- hemizygous females - only a tassel of short microtubules forms with two barely separated daughter centrosomes [10].
• Thus, both classes of alpha-tubulin isotype present in the mature oocyte, alpha TUB67C and alpha TUB84B/84D, are essential for normal spindle function in early Drosophila development [11].
• An involvement of polyglycylated tubulin in axoneme motility is suggested since AXO 49 and TAP 952 specifically inhibit the reactivated motility of sea urchin spermatozoa [12].

Associations of alphaTub84B with chemical compounds

• We show that this second-site noncomplementing mutation is a missense mutation in alpha-tubulin that results in substitution of methionine in place of valine at amino acid 177 [13].
• P4 is precipitated with vinblastine sulfate and migrates as a tubulin subunit [14].
• Drosophila microsomes exhibited tocopherol-omega-hydroxylase activity in the order of delta-T > gamma-T >> alpha-T, a pattern consistent with the effect of PBO in vivo [15].

Physical interactions of alphaTub84B

• GAGA factor and TBF1 bind DNA elements that direct ubiquitous transcription of the Drosophila alpha 1-tubulin gene [16].

Regulatory relationships of alphaTub84B

• Fusion of ftz to the Tubalpha1 promoter resulted in low-level ectopic expression of FTZ relative to FTZ expressed from the endogenous ftz gene [17].
• However, HOXA-2 expressed from a Tubulin alpha 1 promoter was unable to direct maxillary palp determination when either ectopically expressed in the antenna or in the maxillary palp primordia of a pb null mutant [18].

Other interactions of alphaTub84B

• Two of the genes, alpha 1 and alpha 3, are constitutively expressed and code for proteins that are very similar to previously sequenced alpha-tubulins [19].

Analytical, diagnostic and therapeutic context of alphaTub84B

• Western blots of 1D gels of proteins from epidermis, limb buds, or claw muscle showed tissue- and stage-specific changes in tubulin content; similar analyses on blots of 2D gels revealed differences in the number of alpha-tubulin isoforms that were expressed [8].
• In immunofluorescence observations with antibodies against alpha-tubulin, the microtubules appear to radiate from two bright foci widely separated from each other [20].

References