Disease relevance of sc

• The gypsy insulator, a 350-bp element isolated from the Drosophila gypsy retrovirus, contains twelve degenerate binding sites for the Suppressor of Hairy-wing [Su(Hw)] protein [1].

Psychiatry related information on sc

• They most likely mediate ac self-stimulation and sc trans-activation [2].

High impact information on sc

• The development of most epidermal sensory organs in Drosophila is controlled by achaete and scute, two of the genes of the achaete-scute complex (AS-C) [3].
• One major numerator element on the X chromosome is sisterless-b (sis-b), also called scute, which encodes an HLH-type transcription factor [4].
• Their mutant phenotypes are stronger the closer the lesions are to the structural gene of one transcript (T4 RNA) [5].
• We show here that this communication is regulated by Osa, which is recruited by Pannier and Chip. Osa belongs to Brahma chromatin remodeling complexes and we show that Osa negatively regulates ac/sc [6].
• This enhancer promotes Scute protein accumulation in these cells, an event essential for sensory organ development in the absence of other AS-C genes [7].

Biological context of sc

• Embryos deficient for the lethal of scute gene fail to activate hunchback in some neural lineages in a pattern consistent with the lack of a member of a multigene family [8].
• By the use of transfection assays and in vitro binding experiments, here we show that da/sis-b heterodimers bind several sites on the Sxl early promoter with different affinities and consequently tune the level of active transcription from this promoter [9].
• This expression is independent of the ac and sc endogenous genes, indicating that the enhancers respond to local combinations of factors (prepattern) [10].
• Zygotically expressed sisB and maternal daughterless (da) proteins are known to form heterodimers that bind E-box sites and activate transcription [11].
• To further analyze the function of proneural genes, we have studied the effects of Gal4-mediated expression of lethal of scute, a member of the AS-C, during embryogenesis [12].

Anatomical context of sc

• Lack of synergistic lethality among mutations in sc, twist, and dorsal argue against a proposed role for sc in mesoderm formation that had seemed potentially relevant to sex-pathway recruitment [13].
• scute expression in Calliphora vicina reveals an ancestral pattern of longitudinal stripes on the thorax of higher Diptera [14].
• achaete, but not scute, is dispensable for the peripheral nervous system of Drosophila [15].
• We found that germ cells simultaneously heterozygous for sc, sis-a, run and a deficiency for Sxl transplanted into wild-type female hosts develop into functional oocytes [16].
• Three structurally homologous proneural genes--achaete (ac), scute (sc), and lethal of scute (l'sc)--are required for neural stem cell formation [17].

Associations of sc with chemical compounds

• In its 3' untranslated region, Sc RNA contains uridine stretches, putative Sxl protein DNA-binding sites [18].

Physical interactions of sc

• Finally, we provide the first direct evidence that Sc forms heteromeric complexes in vivo in early embryos with the maternally derived helix-loop-helix protein Daughterless [19].
• The known proneural antagonists either titrate these proteins by forming inactive complexes (extramacrochaetae) or repress achaete/scute expression at specific sites (i.e., hairy) [20].

Regulatory relationships of sc

• Hedgehog and Lethal of scute activate Engrailed in these anterior cells [21].
• Despite similarities in function and expression between the Drosophila proneural genes, amos is regulated in a fundamentally different way from scute and atonal [22].

Other interactions of sc

• The yellow locus is the most distal and is followed, proximally, by the achaete and the scute loci [5].
• When one of these spatial restrictions is eliminated, by ubiquitously expressing ac-sc, SMCs still emerge within minima of emc [23].
• In the embryo, ase is expressed in neural precursor cells, a pattern consistent with the known requirement of sc gamma for the development of the larval nervous system [24].
• Forced expression of phyl rescues ES organ formation in ac and sc double mutants. phyl and senseless, encoding a Zn-finger transcriptional factor, depend on each other in ES organ development [25].
• Moreover, chn is activated by ac/sc in proneural clusters [26].

Analytical, diagnostic and therapeutic context of sc

• Our results strongly support the model of negative regulation of emc on ac and sc transcription through titration of their products [2].
• In situ hybridizations to Hw49c and Hw1 larval sections show that the overexpression causes an abnormally generalized distribution of T4 and/or T5 transcripts in imaginal discs [27].
• In transient expression assays in cell culture, both proteins were found to attenuate the transcriptional activation mediated by the proneural bHLH proteins LETHAL OF SCUTE and DAUGHTERLESS at the Enhancer of split promoter [28].

References