title: Localization of RR-1 and RR-2 cuticular proteins within the cuticle of Anopheles gambiae.
abstract: The largest arthropod cuticular protein family, CPR, has the Rebers and Riddiford (R&R) Consensus that in an extended form confers chitin-binding properties. Two forms of the Consensus, RR-1 and RR-2, have been recognized and initial data suggested that the RR-1 and RR-2 proteins were present in different regions within the cuticle itself. Thus, RR-2 proteins would contribute to exocuticle that becomes sclerotized, while RR-1s would be found in endocuticle that remains soft. An alternative, and more common, suggestion is that RR-1 proteins are used for soft, flexible cuticles such as intersegmental membranes, while RR-2s are associated with hard cuticle such as sclerites and head capsules. We used TEM immunogold detection to localize the position of several RR-1 and RR-2 proteins in the cuticle of Anopheles gambiae. RR-1s were localized in the procuticle of the soft intersegmental membrane except for one protein found in the endocuticle of hard cuticle. RR-2s were consistently found in hard cuticle and not in flexible cuticle. All RR-2 antibodies localized to the exocuticle and four out of six were also found in the endocuticle. Hence the location of RR-1s and RR-2s depends more on properties of individual proteins than on either hypothesis.
authors.affiliation: Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Vannini
authors.affiliation: Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA. Electronic address: jhwillis@uga.edu.
authors.forename: Judith H
authors.initials: JH
authors.lastname: Willis
mesh_terms: D000818:Animals; D000852:Anopheles / Q000378:metabolism*; D000906:Antibodies / Q000737:chemistry; D002462:Cell Membrane / Q000378:metabolism; D002686:Chitin / Q000737:chemistry / Q000378:metabolism; D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D019476:Insect Proteins / Q000378:metabolism*; D008854:Microscopy, Electron; D046529:Microscopy, Electron, Transmission; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding
chemical_list: D000906:Antibodies; D019476:Insect Proteins; D010455:Peptides; C047663:cuticle proteins, insects; D002686:Chitin
keywords: EM immunolocalization; Endocuticle; Exocuticle; Intersegmental membrane; Rebers & Riddiford Consensus; Sclerite