Molecular survey of the phosphoserine phosphatase involved in L‐serine synthesis by silkworms (Bombyx mori)

Abstract

Phosphoserine phosphatase (PSP) catalyses the synthesis of l‐serine via the phosphorylated pathway by facilitating the dephosphorylation of phosphoserine. A cDNA encoding PSP from the silkworm Bombyx mori (bmPSP) was isolated using reverse transcription‐PCR and then sequenced. The resulting clone encoded 236 amino acids with a molecular weight of 26 150, exhibiting 14–60% sequence identity with other PSPs. The recombinant PSP was overexpressed in Escherichia coli and purified. Kinetic studies showed that bmPSP possessed activity toward l‐phosphoserine, and Asp20, Asp22 and Asp204 in bmPSP were found to be critical for modulating bmPSP activity. Real‐time PCR analysis provided evidence that the amount of bmpsp transcript was reduced in middle silk glands of a sericin‐deficient silkworm strain. These findings revealed that bmPSP may play important roles in synthesizing one‐carbon donors of l‐serine, which is abundant in silk, as well as other cell metabolites in B. mori.

D‐3‐phosphoglycerate dehydrogenase from the silkworm Bombyx mori: Identification, functional characterization, and expression

“…Indeed, low‐level expression of PHGDH was also observed in human peripheral blood cells (Klomp et al, 2000). Similar results for B. mori PSAT (bmPSAT) and PSP (bmPSP) were obtained (Haque et al, 2019, 2020). Further studies on the developmental changes in these enzymes are warranted to examine their role in silkworm hemocytes.…”

“…(c) Enzyme activity was monitored at pH 7.0 with various temperatures from 20°C to 80°C. (d) Thermostability was determined by incubating the enzyme solution at different temperatures for 30 min before the measurement of remaining activity (bmPSP; Haque et al, 2019Haque et al, , 2020, the silkworm possesses the phosphorylated pathway. L-Serine is involved in protein production and the synthesis of molecules essential for survival and higher functions in living cells (Snell, 1984;Snyder & Kim, 2000).…”

“…In this study, we found the presence of PHGDH in the silkworm, B. mori . Since we already identified B. mori PSAT (bmPSAT) and PSP (bmPSP; Haque et al, 2019, 2020), the silkworm possesses the phosphorylated pathway. l ‐Serine is involved in protein production and the synthesis of molecules essential for survival and higher functions in living cells (Snell, 1984; Snyder & Kim, 2000).…”

The Phosphoserine Phosphatase Alters the Free Amino Acid Compositions and Fecundity in Cyrtorhinus lividipennis Reuter

“…PSPs, which have been found in all three domains of life (eukaryotes, prokaryotes, and archaea), belong to the haloacid dehalogenase-like hydrolase superfamily [ 28 ]. In the last three decades, the PSP gene has been functionally characterized in various organisms such as Hydrogenobacter thermophilus [ 28 ], Entamoeba histolytica [ 29 ], Mycobacterium tuberculosis [ 30 ], Bombyx mori [ 31 ], and in Homo sapiens [ 32 ]. However, in most of the class Insecta members, including C. lividipennis , the deeper molecular understanding of PSP has not been documented.…”

Impact of the rearing environment on the metabolism of shrimps and tracing the origins and species of shrimps using specific metabolites

“…Phosphoserine phosphatase (PSP) promotes the dephosphorylation of phosphoserine and catalyses the synthesis of L-serine through the phosphorylated pathway. 59 Phosphoserine closely resembles L-glutamate structurally, and is one of the elevated phosphomonoesters in the brain of Alzheimer's disease. 60 A metabolic intermediate, glycerol 3-phosphate (G3P, no.…”