1
|
Pan X, Connacher RP, O'Connor MB. Control of the insect metamorphic transition by ecdysteroid production and secretion. CURRENT OPINION IN INSECT SCIENCE 2021; 43:11-20. [PMID: 32950745 PMCID: PMC7965781 DOI: 10.1016/j.cois.2020.09.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/02/2020] [Accepted: 09/07/2020] [Indexed: 05/07/2023]
Abstract
Ecdysteroids are a class of steroid hormones that controls molting and metamorphic transitions in Ecdysozoan species including insects, in which ecdysteroid biosynthesis and its regulation have been extensively studied. Insect ecdysteroids are produced from dietary sterols by a series of reduction-oxidation reactions in the prothoracic gland and in Drosophila they are released into the hemolymph via vesicle-mediated secretion at the time of metamorphosis. To initiate precisely controlled ecdysteroid pulses, the prothoracic gland functions as a central node integrating both intrinsic and extrinsic signals to control ecdysteroid biosynthesis and secretion. In this review, we outline recent progress in the characterization of ecdysone biosynthesis and steroid trafficking pathways and the discoveries of novel factors regulating prothoracic gland function.
Collapse
Affiliation(s)
- Xueyang Pan
- Department of Genetics, Cell Biology and Development, University of Minnesota, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, USA
| | - Robert P Connacher
- Department Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, USA
| | - Michael B O'Connor
- Department of Genetics, Cell Biology and Development, University of Minnesota, USA.
| |
Collapse
|
2
|
Noh JY, Patnaik BB, Tindwa H, Seo GW, Kim DH, Patnaik HH, Jo YH, Lee YS, Lee BL, Kim NJ, Han YS. Genomic organization, sequence characterization and expression analysis of Tenebrio molitor apolipophorin-III in response to an intracellular pathogen, Listeria monocytogenes. Gene 2013; 534:204-17. [PMID: 24200961 DOI: 10.1016/j.gene.2013.10.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 10/21/2013] [Accepted: 10/26/2013] [Indexed: 11/29/2022]
Abstract
Apolipophorin III (apoLp-III) is a well-known hemolymph protein having a functional role in lipid transport and immune response of insects. We cloned full-length cDNA encoding putative apoLp-III from larvae of the coleopteran beetle, Tenebrio molitor (TmapoLp-III), by identification of clones corresponding to the partial sequence of TmapoLp-III, subsequently followed with full length sequencing by a clone-by-clone primer walking method. The complete cDNA consists of 890 nucleotides, including an ORF encoding 196 amino acid residues. Excluding a putative signal peptide of the first 20 amino acid residues, the 176-residue mature apoLp-III has a calculated molecular mass of 19,146Da. Genomic sequence analysis with respect to its cDNA showed that TmapoLp-III was organized into four exons interrupted by three introns. Several immune-related transcription factor binding sites were discovered in the putative 5'-flanking region. BLAST and phylogenetic analyses reveal that TmapoLp-III has high sequence identity (88%) with Tribolium castaneum apoLp-III but shares little sequence homologies (<26%) with other apoLp-IIIs. Homology modeling of Tm apoLp-III shows a bundle of five amphipathic alpha helices, including a short helix 3'. The 'helix-short helix-helix' motif was predicted to be implicated in lipid binding interactions, through reversible conformational changes and accommodating the hydrophobic residues to the exterior for stability. Highest level of TmapoLp-III mRNA was detected at late pupal stages, albeit it is expressed in the larval and adult stages at lower levels. The tissue specific expression of the transcripts showed significantly higher numbers in larval fat body and adult integument. In addition, TmapoLp-III mRNA was found to be highly upregulated in late stages of L. monocytogenes or E. coli challenge. These results indicate that TmapoLp-III may play an important role in innate immune responses against bacterial pathogens in T. molitor.
Collapse
Affiliation(s)
- Ju Young Noh
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Bharat Bhusan Patnaik
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Hamisi Tindwa
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Gi Won Seo
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Dong Hyun Kim
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Hongray Howrelia Patnaik
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Yong Hun Jo
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Yong Seok Lee
- Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan City 336-745 Republic of Korea
| | - Bok Luel Lee
- National Research Laboratory of Defense Proteins, College of Pharmacy, Pusan National University, Jangjeon Dong, Kumjeong Ku, Busan, 609-735, Republic of Korea
| | - Nam Jung Kim
- Division of Applied Entomology, National Academy of Agricultural Science, Rural Development, 61th, Seodun-dong, Gwonseon-gu, Suwon, Gyeonggi-do, 441-853, Republic of Korea
| | - Yeon Soo Han
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea.
| |
Collapse
|