Corazonin

Corazonin is a highly conserved neuropeptide found in many insects, in particular locusts and cockroaches.

Structure

Corazonin is an undecapeptide (11 amino-acid peptide) with the amino acid sequence Glu-Thr-Phe-Gln-Tyr-Ser-Arg-Gly-Trp-Thr-Asn-amide^[1]. It is blocked by pGlu at its N-terminal side and amidated at its C-terminus. This form is called [Arg[7]]-corazonin. Other forms include [His[7]]-corazonin, [Thr[4], His7-corazonin and [Tyr[3], Gln[7], Gln10-corazonin.

History

Corazonin was first identified as a cardiostimulatory neuropeptide in the American cockroach (Periplaneta americana). Due to its ability to accelerate the heart beat in P. americana it was named corazonin, from 'corazon', the Spanish word for 'heart'.

When first identified in locusts, corazonin was initially named 'dark-color-inducing neurohormone' or 'dark pigmentotropin' due to its ability to induce dark pigmentation in some insects.

Where corazonin is found

[Arg[7]]-corazonin was originally identified in cockroaches such as the American cockroach (Periplaneta americana).

[His[7]]-corazonin is found in certain locusts, including the migratory locust (Locusta migratoria) and the desert locust (Schistocerca gregaria), the stick insect Carausius morosus, and in wasps (Vespidae).

[Thr[4], His7-corazonin appears only to be found in bees, such as the honey bee (Apis mellifera).

[Tyr[3], Gln[7], Gln10-corazonin is present in wasps.

Corazonin has also been identified in the genus of flies Drosophila, the cricket Gryllus bimaculatus and the silkworm Bombyx mori.

Function

Corazonin has no universally recognized function.

In the American cockroach Periplaneta americana, [Arg[7]]-corazonin acts as a cardiostimulatory neuropeptide and accelerates the heart beat^[1]. It also causes contractions of the hyperneural muscle^[2], however this has not been seen in other cockroach species.

[His[7]]-corazonin acts as a hormonal factor in locusts and can cause dark pigmentation in albino migratory locusts (Locusta migratoria)^[3] and in green nymphs of the desert locust Schistocerca gregaria. While corazonins found in crickets and moths have no effect on body colour of the crickets or moths themselves, they can cause dark pigmentation in albino nymphs of the migratory locust (Locusta migratoria)^[4].

In silkworms (Bombyx mori), corazonin reduces the spinning rate of silk.^[5]

References

• Nässel DR (2002). "Neuropeptides in the nervous system of Drosophila and other insects: multiple roles as neuromodulators and neurohormones". Progress in Neurobiology 68 (1): 1-84. doi:10.1016/S0301-0082(02)00057-6 PMID 12427481

1. ^ ^{a b} Veenstra JA (1989). "Isolation and structure of corazonin, a cardioactive peptide from the American cockroach". FEBS Letters 250 (2): 231-234. doi:10.1016/0014-5793(89)80727-6
2. ^ Predel R, Agricola H, Linde D, Wollweber L, Veenstra JA and Penzlin H (1994). "The insect neuropeptide corazonin: physiological and immunocytochemical studies in Blattariae". Zoology 98: 35–50.
3. ^ Tawfik AI, Tanaka S, De Loof A, Schoofs L, Baggerman G, Waelkens E, Derua R, Milner Y, Yerushalmi Y and Pener MP (1999). "Identification of the gregarization-associated dark-pigmentotropin in locusts through an albino mutant". Proc. Natl. Acad. Sci. U.S.A. 96 (12): 7083–7087. link
4. ^ Hua YJ, Ishibashi J, Saito H, Tawfik AI, Sakakibara M, Tanaka Y, Derua R, Waelkens E, Baggerman G, De Loof A, Schoofs L, and Tanaka S (2000). "Identification of [Arg7] corazonin in the silkworm, Bombyx mori, and the cricket, Gryllus bimaculatus, as a factor inducing dark color in an albino strain of the locust, Locusta migratoria". Journal of Insect Physiology 46 (6): 853–859. doi:10.1016/S0022-1910(99)00173-0
5. ^ Tanaka Y, Huab YJ, Roller L and Tanaka S (2002). "Corazonin reduces the spinning rate in the silkworm, Bombyx mori". Journal of Insect Physiology 48 (7): 707-714. doi:10.1016/S0022-1910(02)00094-X