Figure 1.
Phylogenetic relationship of the NPSR, CCAPR, GnRHR and vasopressin-like receptors from vertebrates and invertebrates.
Bayesian tree of NPSR (red), invertebrate NPSR-like receptor (orange), CCAPR (green), V1AR (blue), V1BR (blue), OTR (blue), V2R (blue), GnRHR (vertebrate and invertebrate Gonadotropin releasing hormone receptor) and VPR (invertebrate vasopressin-like receptor) (blue) sequences. The tree was generated using the Bayesian approach in MrBayes 3.1.2 using JTT+F+I+G model. Bayesian posterior probabilities are marked near branches as a percentage and are used as confidence values of tree branches. Nodes were compressed to represent the animal lineages. Scale bar represents the number of estimated changes per site for a unit of branch length. The receptor group abbreviations, names and accession numbers of the sequences and common and binomial names of the species are as listed in Table S2. In this figure and in Figure 4, the sequence names marked with * and +symbols represent manually corrected sequences at the N terminus and C terminus, respectively. Sequence names marked with ‡ symbol in this figure represent fragmented sequences.
Figure 2.
Schematic diagram of the human neuropeptide S receptor.
The sequence is drawn and labeled according to the extracellular, intracellular and transmembrane regions. The boundaries of the three regions were based on the definition of these regions for human NPSR [GenBank: NP_997055] given by the Ballesteros-Weinstein nomenclature and TMHMM program. The most conserved residue in each transmembrane helix is denoted with red text. The first and last amino acid residue numbers in each helix is indicated using Ballesteros-Weinstein numbering scheme. Residues that represent sites of functional divergence between the NPSR and the V1AR, V1BR, V2R and OTR subtypes are marked with outlined circles. Residue-wise functional divergence of NPSR with each subtype of vasopressin-like receptor is provided in Data S3.
Figure 3.
Multiple alignment of functionally divergent sites in the NPSR and vasopressin-like receptors.
Samplings of selected functional divergence-related positions in the region starting from TM2 to the end of ECL3 are shown. Amino acid positions (marked on top) are identified by Ballesteros-Weinstein numbering corresponding to the residue position in human NPSR. Contiguous blocks of conserved residues in the NPSR are shown within hollow boxes. Residues associated with Type I and II divergence are marked in blue background and red background, respectively (Data S3).
Figure 4.
Conservation and variability of intron positions and phases.
Schematic of the multiple alignment of amino acid sequences of the NPSR, NPSR-like and representatives from the CCAPR and vasopressin-like receptor subtypes are shown. The 0, 1, 2 phase introns are marked with black, red and green lines, respectively. Introns corresponding to human NPSR are named I to VIII according to their positions in the amino acid sequence. The gene structure details of all sequences indicating exon-intron lengths, intron positions and phases are presented in Figure S3, S4 and Data S2.
Table 1.
Type I and Type II functional divergence between the NPSR and vasopressin-like receptor subtypes.