Proteolytic enzymes of female Anopheles: Biphasic synthesis, regulation, and multiple feeding

Hörler, Emanuel; Briegel, Hans J.

doi:10.1002/arch.940280208

Cited by 24 publications

(17 citation statements)

References 37 publications

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“…Distention-induced inhibition begins with the activation of abdominal stretch receptors and acts until the bloodmeal has been digested and excreted, and the abdominal distention has been reduced (Klowden andLea 1978, 1979b). The humoral mechanism starts when a bloodmeal initiates egg maturation and prevents host seeking from continuing (Klowden and Lea 1979a, Klowden 1981, Horler and Briegel 1995. Klowden and Briegel (1994) argued that the two mechanisms often overlap in Ae.…”

Section: Discussionmentioning

confidence: 99%

Multiple Blood Feeding and Host-Seeking Behavior in Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

2013

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The body size of mosquitoes can influence a number of bionomic factors, such as their blood-feeding ability, host attack rate, and fecundity. All of these traits are important determinants of their potential to transmit diseases. Among abiotic and biotic factors, high temperature and low nutrition in the developing stages of mosquitoes generally result in small adults. We studied the relationship between body size and multiple feeding in a gonotrophic cycle and some fecundity attributes by using three strains of two competent vector species, Aedes aegypti (L.) and Aedes albopictus (Skuse). We raised small and large mosquitoes under low and high food conditions in the laboratory to measure parameters of fecundity and blood-feeding behavior. Fecundity was positively correlated with body size in both species, whereas the number of bloodmeals, the frequency of host-seeking behavior, and egg retention were negatively correlated with body size in the Ae. albopictus Nagasaki strain. We found that multiple feeding and host-seeking behavior were negatively correlated with body size, i.e., small mosquitoes tended to have more contact with hosts. We found that two mechanisms that inhibit engorged mosquitoes from seeking out hosts, distension-induced and oocyte-induced inhibition, were not strong enough to limit host-seeking behavior, and multiple feeding increased fecundity. Size-dependent multiple feeding and host-seeking behavior affect contact frequency with hosts and should be considered when predicting how changes in mosquito body size affect disease transmission.

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Section: Discussionmentioning

confidence: 99%

Multiple Blood Feeding and Host-Seeking Behavior in Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

2013

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“…Both assays were further modified as described in Hörler and Briegel (1995). L-1-tosylamid-2-phenylethyl chloromethyl ketone (TPCK, Sigma T 4376; 0.004M in 50% methanol) was used as a specific chymotrypsin inhibitor (Schoellmann and Shaw, 1963).…”

Section: Enzyme Assaysmentioning

confidence: 99%

Chymotrypsin inhibitors in mosquitoes: Activity profile during development and after blood feeding

Hörler

Briegel

1997

Arch. Insect Biochem. Physiol.

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Chymotrypsin and trypsin inhibitors persist throughout all developmental instars of Aedes aegypti. After a blood meal, inhibitor activity against chymotrypsin was more than double that of sugar‐fed females, but only weak activity was detected in midguts where proteinase inhibitors has been thought to regulate proteinases during blood digestion. A fourfold increase in the ratio of abdominal/thoracic inhibitor activity after the blood meal strongly suggested that fat body, or other abdominal tissues, represent the major source of inhibitor. Chymotrypsin inhibitor activity was deposited in maturing oocytes. Similar results were obtained with blood‐fed Anopheles albimanus. Chymotrypsin inhibitor was active against different mosquito proteinases and against bovine α‐chymotrypsin and trypsin, but not against subtilisin, pancreatic elastase, or fungal proteases; chymotrypsin inhibitors did not interfere with bacterial growth. The hypothesis on the regulation of blood digestion through the action of proteinase inhibitors during the gonotrophic cycle was abandoned and its involvement in the phenoloxidase cascade in the mosquito egg chorion is suggested instead. Arch. Insect Biochem. Physiol. 36:315–333, 1997. © 1997 Wiley‐Liss, Inc.

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“…In the Anopheles species An. albimanus , however, early trypsins are stored as zymogens in the gut epithelium and are secreted and activated quickly in response to blood meal ingestion (Horler & Briegel, 1995; Muller et al. , 1995).…”

Section: Introductionmentioning

confidence: 99%

Molecular characterization of two serine proteases expressed in gut tissue of the African trypanosome vector, Glossina morsitans morsitans

Jiang

Cheng

et al. 2001

Insect Molecular Biology

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Serine proteases are major insect gut enzymes involved in digestion of dietary proteins, and in addition they have been implicated in the process of pathogen establishment in several vector insects. The medically important vector, tsetse fly (Diptera:Glossinidiae), is involved in the transmission of African trypanosomes, which cause devastating diseases in animals and humans. Both the male and female tsetse can transmit trypanosomes and both are strict bloodfeeders throughout all stages of their development. Here, we describe the characterization of two putative serine protease-encoding genes, Glossina serine protease-1 (Gsp1) and Glossina serine protease-2 (Gsp2) from gut tissue. Both putative cDNA products represent prepro peptides with hydrophobic signal peptide sequences associated with their 5'-end terminus. The Gsp1 cDNA encodes a putative mature protein of 245 amino acids with a molecular mass of 26 428 Da, while the predicted size of the 228 amino acid mature peptide encoded by Gsp2 cDNA is 24 573 Da. Both deduced peptides contain the Asp/His/Ser catalytic triad and the conserved residues surrounding it which are characteristic of serine proteases. In addition, both proteins have the six-conserved cysteine residues to form the three-cysteine bonds typically present in invertebrate serine proteases. Based on the presence of substrate specific residues, the Gsp1 gene encodes a chymotrypsin-like protease while Gsp2 gene encodes for a protein with trypsin-like activity. Both proteins are encoded by few loci in tsetse genome, being present in one or two copies only. The mRNA expression levels for the genes do not vary extensively throughout the digestive cycle, and high levels of mRNAs can be readily detected in the gut tissue of newly emerged flies. The levels of trypsin and chymotrypsin activities in the gut lumen increase following blood feeding and change significantly in the gut cells throughout the digestion cycle. Hence, the regulation of expression for trypsin and chymotrypsin occurs at the post-transcriptional level in tsetse. Both the coding sequences and patterns of expression of Gsp1 and Gsp2 genes are similar to the serine proteases that have been reported from the bloodfeeding insect Stomoxys calcitrans.

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Proteolytic enzymes of female Anopheles: Biphasic synthesis, regulation, and multiple feeding

Cited by 24 publications

References 37 publications

Multiple Blood Feeding and Host-Seeking Behavior in <I>Aedes aegypti</I> and <I>Aedes albopictus</I> (Diptera: Culicidae)

Multiple Blood Feeding and Host-Seeking Behavior in <I>Aedes aegypti</I> and <I>Aedes albopictus</I> (Diptera: Culicidae)

Chymotrypsin inhibitors in mosquitoes: Activity profile during development and after blood feeding

Molecular characterization of two serine proteases expressed in gut tissue of the African trypanosome vector, Glossina morsitans morsitans

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