Disease relevance of Lac

• Neuroblasts, ganglion mother cells and neurons all express Lachesin early in their lives, but expression becomes restricted to a subset of neurons as development progresses [1].
• One of these is an imperfect palindrome having homology with the lac-operator of Escherichia coli; the other contains a reiterated sequence (5'PyPuT/C TGCATAC/TPyPy) homologous to the octamer that is the core of many enhancers and upstream promoter elements [2].
• We have analyzed the nucleotide sequence changes in the lac promoter-lacZ alpha region of M13mp2 phage induced by treatment of phage-infected Escherichia coli with N4-aminocytidine [3].

High impact information on Lac

• We have assayed the transcriptional activities of wild-type Kr protein as well as Lac repressor/Kr fusion proteins in HeLa and CV-1 cells [4].
• Cloned DNAs from the characteristic bulbous structure at the tip of the X chromosome in the region of the broad complex display an unusual pattern of in situ hybridization [5].
• A sensitive homologous recombination strand-transfer assay is described that employs short radiolabeled double-stranded DNA fragments from the lac/polylinker region of plasmid pUC18 and (+)viral M13mp18 single-stranded DNA as substrates [6].
• Flagellar growth continued within the short rn null cysts to produce large bulbous terminations of intertwined mature flagella [7].
• At the cellular level, we can detect enlarged cells, suggesting that Lac regulates organ size by influencing cell length rather than cell number, and cell detachments, indicating a role for Lac in cell adhesion [8].

Biological context of Lac

• Results from an in vitro assay further support that Lac behaves as a homophilic cell adhesion molecule [8].
• Here we report that Lachesin (Lac), a cell surface protein, is required for the proper morphogenesis of the Drosophila tracheal system [8].
• The Lac repressor/lac operator system was used to label specific chromosomal sites in live tissues, allowing extended observation of chromatin motion in different cell cycle stages [9].
• Models based on the fractional occupancy of defined DNA binding sites have been used to describe the regulation of the lac operon in E. coli and the lysis/lysogeny switch of phage lambda [10].
• Tissue-specific expression of AWD protein from this rescue transgene is identical to tissue-specific expression of beta-galactosidase from a reporter transgene that has the same regulatory region fused to the bacterial lac Z gene [11].

Anatomical context of Lac

• Sensory neurons express Lachesin as they delaminate from the body wall ectoderm [1].
• Grasshopper Lachesin is a 38 x 10(3) M(r) protein linked to cell membranes through a glycosyl phosphatidylinositol anchor [1].
• Lachesin is expressed on the surfaces of differentiating neuronal cells from the onset of neurogenesis in both the central and peripheral nervous systems [1].
• The IgLON protein Lachesin is required for the blood-brain barrier in Drosophila [12].
• We selected a line of flies with a P insertion, carrying the Escherichia coli lac Z gene, which showed beta-galactosidase expression in the nurse cell nuclei during oogenesis [13].

Associations of Lac with chemical compounds

• Lac color and cochineal extract showed inhibition against IQ, MeIQx, AFB1, 2-AAF and DMBA [14].
• In an E.coli lac Z reversion assay, expression of DmAGT efficiently suppressed MNNG-induced G:C-->A:T as well as A:T-->G:C transition mutations in vivo [15].
• Four anthraquinone pigments (alizarin, purpurin, lac color, and cochineal extract) showed significant antigenotoxic activities [14].

Other interactions of Lac

• Lachesin expression begins in some cells of the neurogenic ectoderm immediately after engrailed expression begins in the posterior cells of each future segment [1].

References