title: Structural similarities between mRNA for the formyl peptide receptors and 18S rRNA.
abstract: Formyl peptides released by some bacteria are powerful chemoattractants and activators of mammalian granulocytes and monocytes, acting through 7-transmembrane specific formyl peptide receptors (FPRs). Three distinct segments of the formyl peptide receptor 1 (FPR1) mRNA of Man share probabilistically significant homologies with segments of the 18S rRNA which are highly conserved from Drosophila to Man. Overall, the three segments cover approximately 24% that of the 18S rRNA sequence and approximately 36% of the FPR1 sequence. The three segments are, however, arranged in different orders in the 18S rRNAs and in the FPR1 mRNA, the segment appearing in the first location in the 18S rRNAs is located at the end of the FPR1 mRNA sequence. The hypothesis is advanced that the three "conserved" segments either derive from an ancestral gene that is the forerunner of both the ribosomal 18S genes and the FPR genes or that at some stage of evolution the FPR genes derived, at least in part, from the more ancient ribosomal 18S genes. The extant 18S rRNA sequences exhibit obvious signs of a number of breaks that occurred during evolution, especially in the transition from insects to vertebrates. Some of these events may have resulted in differential rearrangements of segments in the groups of FPR genes and ribosomal 18S genes.
authors.affiliation: Department of Human Anatomy and Histology, University of Bari, Bari, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: Panaro
authors.forename: A
authors.initials: A
authors.lastname: Acquafredda
authors.forename: M
authors.initials: M
authors.lastname: Sisto
authors.forename: S
authors.initials: S
authors.lastname: Lisi
authors.forename: R
authors.initials: R
authors.lastname: Calvello
authors.forename: M
authors.initials: M
authors.lastname: Saccia
authors.forename: A B
authors.initials: AB
authors.lastname: Maffione
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Mitolo
mesh_terms: D000818:Animals; D001483:Base Sequence; D002645:Chickens; D016384:Consensus Sequence / Q000235:genetics; D017124:Conserved Sequence; D004330:Drosophila; D019143:Evolution, Molecular; D015321:Gene Rearrangement; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics*; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D019718:Receptors, CXCR4 / Q000235:genetics; D044042:Receptors, Formyl Peptide / Q000235:genetics*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014981:Xenopus
chemical_list: C469986:FPR1 protein, human; D012333:RNA, Messenger; D012337:RNA, Ribosomal, 18S; D019718:Receptors, CXCR4; D044042:Receptors, Formyl Peptide