Abstract:As a member of the tryptophan-aspartate repeat (WD-repeat) family of proteins, the receptor for activated C kinase 1 (RACK1) is an intracellular adaptor protein that plays an important role in the regulation of various signaling pathways. In this study, the guanine-nucleotide-binding protein beta polypeptide 2-like 1(GNB2L1) gene encoding RACK1 protein was obtained from the gonad of Paramisgurnus dabryanus by rapid amplification of cDNA ends (RACE). The full-length cDNA of the GNB2L1 gene is 1 115 bp and contains an open reading frame of 965 bp, encoding for a putative RACK1 protein with 317 amino acids. The GNB2L1 gene was also isolated from the gonad of Misgurnus anguillicaudatus by gene cloning technique, of which the encoding cDNA sequence is 965 bp long and encodes a putative RACK1 protein with 317 aa. Sequence analysis showed that RACK1 proteins of two loaches display 94%-97% sequence similarities to those of other teleost (Fig.1), and the GNB2L1 genes in vertebrate, including in teleost, have seven introns and eight exons (Fig.2). The phylogenetic tree based on multiple sequence alignment of GNB2L1 genes of two loaches and other closely related teleost revealed that the closest relationship to M. anguillicaudatus and P. dabryanus (Fig.4). Semi-quantative RT-PCR confirmed that GNB2L1 gene is expressed ubiquitously in many P. dabryanus tissues, especially higher in brain (Fig.3). These results implied that GNB2L1 gene is strongly conserved through evolution, and may be essential for cellular functions in P. dabryanus.