High impact information on Ptth

• PER-positive neurons and their projections are strategically positioned for regulating prothoracicotropic hormone and eclosion hormone, two neurohormones under circadian control [1].
• The prothoracicotropic hormone (PTTH) of Drosophila melanogaster is a modulator of ecdysteroid (molting hormone) synthesis and was isolated and characterized from extracts of whole larvae (approximately 4 x 10(5) larvae) [2].
• The molecular weight of the purified PTTH was 45 kDa and N-terminal amino acid sequence analysis indicated that those analyzed sequences displayed no significant homology with known peptides or peptide hormones, including PTTH from the silkmoth, Bombyx mori [2].
• Once critical weight is reached, juvenile hormone (JH) titers decline, resulting in the release of prothoracicotropic hormone (PTTH) at the next photoperiod gate and thereby inducing metamorphosis [3].
• Brain neurons immunoreactive with antibodies to bombyxin, PTTH, and DH are in strikingly similar positions to their lepidopteran counterparts, indicating that at least some Drosophila neuroendocrine cells are homologous to those of lepidopterans [4].

Biological context of Ptth

• In Rhodnius prolixus (Hemiptera), the brain neuropeptide prothoracicotropic hormone (PTTH) is released with a circadian rhythm that is controlled by paired photosensitive clocks in the brain [5].

Anatomical context of Ptth

• An extract prepared from the Drosophila larval central nervous system, that presumably contains prothoracicotropic hormone, elicits a significant and dose-dependent in vitro increase in ecdysteroid synthesis by ring glands from wandering third instar larvae [6].

Associations of Ptth with chemical compounds

• The temperature-sensitive mutation 1(3)ecd1 of Drosophila melanogaster is known to autonomously impair the ability of the larval prothoracic gland to produce the steroid molting hormone ecdysone in response to stimulation by the tropic neuropeptide prothoracicotropic hormone [7].
• Manipulations of the glands' hormonal milieu showed that hsc 70 mRNA levels respond to 20-hydroxyecdysone, dibutyryl cAMP, PTTH and the JH analogue hydroprene [8].
• To investigate the cell-specific expression in the brain, we constructed recombinant C4/B3::EGFP-BmNPV and PTTH::EGFP-BmNPV which carry the EGFP gene under the control of bombyxin B3 and prothoracicotropic hormone (PTTH) gene promoters, respectively [9].

Other interactions of Ptth

• Two of these mutants, dlg and dco, show abnormally strong immunoreactivity for allatotropin during the extended larval period and the former also show increased staining with the PTTH antibody [4].
• The ecdysteroidogenic P450 Cyp302a1/disembodied from the silkworm, Bombyx mori, is transcriptionally regulated by prothoracicotropic hormone [10].

Analytical, diagnostic and therapeutic context of Ptth

• Western blot analysis indicated that the native form of Drosophila PTTH was a single 66-kDa polypeptide with N-linked carbohydrate chains and intrachain disulfide bonds [2].

References