title: Recombinant expression and functional analysis of a Chlamydomonas reinhardtii bacterial-type phosphoenolpyruvate carboxylase gene fragment.
abstract: To investigate the function of a bacterial-type phosphoenolpyruvate carboxylase (PEPC2) derived from photosynthetically-grown Chlamydomonas reinhardtii, a fragment of the pepc2 gene was cloned and expressed in Escherichia coli. After optimal induction for 6 h, PEPC activity in the reverse mutant was lower than wild type (0.9 vs. 1.7 U/mg protein), and soluble protein was also lower than wild type (119 vs. 186 mg/g dry wt). In contrast, the total lipid content was increased from 56 (in wild type) to 71 mg/g dry wt, despite the growth rate being slightly diminished. The changes in PEPC activity, soluble protein and total lipid in the forward mutant were the opposite (2.4 U/mg, 230 mg/g, and 44 mg/g dry wt, respectively). Together, these data indicate that PEPC may function as a metabolic pivot in the regulation of protein and lipid accumulation in this alga.
authors.affiliation: College of Fisheries & Life Sciences, Shanghai Ocean University, No. 999, Hucheng Ring Road, Shanghai, China, waichifanqie@126.com.
authors.forename: Qi-Lin
authors.initials: QL
authors.lastname: Tian
authors.forename: Ding-Ji
authors.initials: DJ
authors.lastname: Shi
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Jia
authors.forename: Hua-Ling
authors.initials: HL
authors.lastname: Mi
authors.forename: Xi-Wen
authors.initials: XW
authors.lastname: Huang
authors.forename: Pei-Min
authors.initials: PM
authors.lastname: He
mesh_terms: D020418:Algal Proteins / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000201:enzymology* / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D050356:Lipid Metabolism; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D059386:Reverse Genetics
chemical_list: D020418:Algal Proteins; D011994:Recombinant Proteins; D010730:Phosphoenolpyruvate Carboxylase