Structure and Expression Analysis of vv-SPK Gene in VEGF Signaling Pathway of Volvariella volvacea

VEGF signaling pathway regulates cell proliferation, differentiation, migration, stress response, and survival of fungi. A gene, vv-SPK, in the pathway coding SPK protein from the mushroom, Volvariella volvacea, was obtained. A structure analysis showed that the gene was 1 996 bp, including 11 introns, and the open reading frame (ORF) of 1 401 bp encoding 466 amino acids. BLASTP comparison showed vv-SPK sharing a high similarity with the genes from Galerina patagonica, Laccaria bicolor and Laccaria amethystine. RT-qPCR verified the gene expression of SPK protein being associated with the stipe elongation. Since SPK, with its protein kinase characteristics, involves in the cell proliferation pathway in VEGF, the protein was postulated to play a significant role in enhancing the cell division during the stipe development of V. volvacea. There might also be a SPK-mediated signaling pathway that promoted the cell proliferation in V. volvacea.