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Could protein tertiary structure influence mammary transgene expression more than tissue specific codon usage?

He Z, Zhao Y, Mei G, Li N, Chen Y - Transgenic Res. (2010)

Bottom Line: Animal mammary glands have been successfully employed to produce therapeutic recombinant human proteins.However, considerable variation in animal mammary transgene expression efficiency has been reported.We now consider whether aspects of codon usage and/or protein tertiary structure underlie this variation in mammary transgene expression.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, 510006, Guangzhou, People's Republic of China.

ABSTRACT
Animal mammary glands have been successfully employed to produce therapeutic recombinant human proteins. However, considerable variation in animal mammary transgene expression efficiency has been reported. We now consider whether aspects of codon usage and/or protein tertiary structure underlie this variation in mammary transgene expression.

Show MeSH
Expression levels of recombinant human proteins in the milk of transgenic animals. The expression level of each protein presents the highest one among different studies summarized in Table 1; ATCD20 IgH and ATCD20 IgL indicate the heavy and light chain of human anti-CD20 monoclonal antibody; FGA, FGB and FGG note the alpha chain, beta chain and gamma chain of fibrinogen (FIB) respectively; mCol18a1 stands for mouse collagen, type XVIII, alpha 1; star notes the expression level of recombinant protein with a cDNA based expression construct; open circle indicates the expression level values of hFVIII(0.0027 mg/mL), hIL-2(0.000043 mg/mL) and mCol18a1(0.00003 mg/mL) which all are too low to be fully presented on the top of the bar
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Fig2: Expression levels of recombinant human proteins in the milk of transgenic animals. The expression level of each protein presents the highest one among different studies summarized in Table 1; ATCD20 IgH and ATCD20 IgL indicate the heavy and light chain of human anti-CD20 monoclonal antibody; FGA, FGB and FGG note the alpha chain, beta chain and gamma chain of fibrinogen (FIB) respectively; mCol18a1 stands for mouse collagen, type XVIII, alpha 1; star notes the expression level of recombinant protein with a cDNA based expression construct; open circle indicates the expression level values of hFVIII(0.0027 mg/mL), hIL-2(0.000043 mg/mL) and mCol18a1(0.00003 mg/mL) which all are too low to be fully presented on the top of the bar

Mentions: Successful examples of expressing recombinant human proteins in transgenic animals to date are summarized in Table 1 and the greatest expression level of the 31 recombinant proteins reported in Table 1 were showed in Fig. 2. When comparing codon usage of the 31 recombinant proteins expressed in the milk of transgenic animals to human mammary gland specific genes and milk proteins, we found several most efficiently expressed recombinant human proteins (SERPINC1, ATCD20IgL, REG3A, LTF, FGA, FGB and FGG) were clustered close to the mammary gland specific genes and milk proteins. However, we also found the moderately expressed FIX and those less efficiently expressed recombinant proteins (LYZ, CAT, IL2 and mCol18a1) were clustered close to most human mammary gland specific genes and milk proteins. The observed three classes of genes can not be discriminated from each other (mammary gland, P = 0.574; milk proteins, P = 0.900; supplementary Fig. 7). Similar results can be observed in the comparing of recombinant proteins to mouse mammary gland specific genes and milk proteins (mammary gland, P = 0.952; milk proteins, P = 0.974; supplementary Fig. 8). Further comparing codon usage of milk proteins among 19 different mammals showed that most milk proteins were prone to use similar codon usage patterns among different mammalian species (supplementary Fig. 9). Thus we compared the codon usage of recombinant proteins to milk proteins in the main five livestock cow, sheep, goat, rabbit and pig. In each animal, except for certain proteins, the cluster result was quite similar to human and mouse (Fig. 3). Thus we dismiss our proposal that expression levels of recombinant human proteins in the milk of transgenic animals correlate with mammary gland specific codon usage patterns.Table 1


Could protein tertiary structure influence mammary transgene expression more than tissue specific codon usage?

He Z, Zhao Y, Mei G, Li N, Chen Y - Transgenic Res. (2010)

Expression levels of recombinant human proteins in the milk of transgenic animals. The expression level of each protein presents the highest one among different studies summarized in Table 1; ATCD20 IgH and ATCD20 IgL indicate the heavy and light chain of human anti-CD20 monoclonal antibody; FGA, FGB and FGG note the alpha chain, beta chain and gamma chain of fibrinogen (FIB) respectively; mCol18a1 stands for mouse collagen, type XVIII, alpha 1; star notes the expression level of recombinant protein with a cDNA based expression construct; open circle indicates the expression level values of hFVIII(0.0027 mg/mL), hIL-2(0.000043 mg/mL) and mCol18a1(0.00003 mg/mL) which all are too low to be fully presented on the top of the bar
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2902731&req=5

Fig2: Expression levels of recombinant human proteins in the milk of transgenic animals. The expression level of each protein presents the highest one among different studies summarized in Table 1; ATCD20 IgH and ATCD20 IgL indicate the heavy and light chain of human anti-CD20 monoclonal antibody; FGA, FGB and FGG note the alpha chain, beta chain and gamma chain of fibrinogen (FIB) respectively; mCol18a1 stands for mouse collagen, type XVIII, alpha 1; star notes the expression level of recombinant protein with a cDNA based expression construct; open circle indicates the expression level values of hFVIII(0.0027 mg/mL), hIL-2(0.000043 mg/mL) and mCol18a1(0.00003 mg/mL) which all are too low to be fully presented on the top of the bar
Mentions: Successful examples of expressing recombinant human proteins in transgenic animals to date are summarized in Table 1 and the greatest expression level of the 31 recombinant proteins reported in Table 1 were showed in Fig. 2. When comparing codon usage of the 31 recombinant proteins expressed in the milk of transgenic animals to human mammary gland specific genes and milk proteins, we found several most efficiently expressed recombinant human proteins (SERPINC1, ATCD20IgL, REG3A, LTF, FGA, FGB and FGG) were clustered close to the mammary gland specific genes and milk proteins. However, we also found the moderately expressed FIX and those less efficiently expressed recombinant proteins (LYZ, CAT, IL2 and mCol18a1) were clustered close to most human mammary gland specific genes and milk proteins. The observed three classes of genes can not be discriminated from each other (mammary gland, P = 0.574; milk proteins, P = 0.900; supplementary Fig. 7). Similar results can be observed in the comparing of recombinant proteins to mouse mammary gland specific genes and milk proteins (mammary gland, P = 0.952; milk proteins, P = 0.974; supplementary Fig. 8). Further comparing codon usage of milk proteins among 19 different mammals showed that most milk proteins were prone to use similar codon usage patterns among different mammalian species (supplementary Fig. 9). Thus we compared the codon usage of recombinant proteins to milk proteins in the main five livestock cow, sheep, goat, rabbit and pig. In each animal, except for certain proteins, the cluster result was quite similar to human and mouse (Fig. 3). Thus we dismiss our proposal that expression levels of recombinant human proteins in the milk of transgenic animals correlate with mammary gland specific codon usage patterns.Table 1

Bottom Line: Animal mammary glands have been successfully employed to produce therapeutic recombinant human proteins.However, considerable variation in animal mammary transgene expression efficiency has been reported.We now consider whether aspects of codon usage and/or protein tertiary structure underlie this variation in mammary transgene expression.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, 510006, Guangzhou, People's Republic of China.

ABSTRACT
Animal mammary glands have been successfully employed to produce therapeutic recombinant human proteins. However, considerable variation in animal mammary transgene expression efficiency has been reported. We now consider whether aspects of codon usage and/or protein tertiary structure underlie this variation in mammary transgene expression.

Show MeSH