Immunogenetics

, Volume 64, Issue 7, pp 549–558

Evolution of the βGRP/GNBP/β-1,3-glucanase family of insects

Original Paper

DOI: 10.1007/s00251-012-0610-8

Cite this article as:
Hughes, A.L. Immunogenetics (2012) 64: 549. doi:10.1007/s00251-012-0610-8

Abstract

The βGRP/GNBP/β-1,3-glucanase protein family of insects includes several proteins involved in innate immune recognition, such as the β-glucan recognition proteins of Lepidoptera and the Gram-negative bacteria-binding proteins of Drosophila. A phylogenetic analysis supported the existence of two distinct subfamilies, designated the pattern recognition receptor (PRR) and glucanase subfamilies, which originated by gene duplication prior to the origin of the Holometabola. In the C-terminal region (CTR) shared by both subfamilies, the PRR subfamily has evolved significantly more rapidly at the amino acid sequence level than has the glucanase subfamily, implying a relative lack of constraint on the amino acid sequence of this region in the PRR subfamily. PRR subfamily members also include an N-terminal region (NTR), involved in carbohydrate recognition, which is not shared by glucanase subfamily members. In comparisons between paralogous PRR subfamily members, there were no conserved amino acid residues in the NTR. However, when pairs of putatively orthologous PRR subfamily members were compared, the NTR was most often as conserved as the CTR or more so. This pattern suggests that the NTR may be important in functions specific to the different paralogs, while amino acid sequence changes in the NTR may have been important in functional differentiation among paralogs, specifically with regard to the types of carbohydrates that they recognize.

Keywords

Beta-1,3-glucanase Beta-glucan recognition protein Gram-negative binding protein Insect immunity Pattern recognition receptor 

Supplementary material

251_2012_610_MOESM1_ESM.pdf (98 kb)
Supplementary Figure S1Alignment of 90 sequences the βGRPs/GNBP/β-1,3-glucanase family (PDF 97 kb)
251_2012_610_MOESM2_ESM.pdf (16 kb)
Supplementary Figure S2ME tree based on the JTT + G distance (a = 1.35) at 171 aligned sites. Values on branches are confidence levels of interior branch test (PDF 16 kb)
251_2012_610_MOESM3_ESM.pdf (48 kb)
Supplementary Figure S3ME tree of hemolymph subfamily members from Diptera and Lepidoptera, based on the JTT + G distance (a = 1.51) at 326 aligned sites. Values on branches are confidence levels of interior branch test (PDF 47 kb)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  1. 1.Department of Biological SciencesUniversity of South CarolinaColumbiaUSA