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The minimal domain of adipose triglyceride lipase (ATGL) ranges until leucine 254 and can be activated and inhibited by CGI-58 and G0S2, respectively.

Cornaciu I, Boeszoermenyi A, Lindermuth H, Nagy HM, Cerk IK, Ebner C, Salzburger B, Gruber A, Schweiger M, Zechner R, Lass A, Zimmermann R, Oberer M - PLoS ONE (2011)

Bottom Line: Yet, neither an experimentally determined 3D structure nor a model of ATGL is currently available, which would help to understand how CGI-58 and G0S2 modulate ATGL's activity.Based on these data, we generated a 3D homology model for the minimal domain.Our data provide insights into the structure-function relationship of ATGL and indicate higher structural similarities in the N-terminal halves of mammalian patatin-like phospholipase domain containing proteins, (PNPLA1, -2,- 3 and -5) than originally anticipated.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria.

ABSTRACT
Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme of lipolysis. ATGL specifically hydrolyzes triacylglycerols (TGs), thereby generating diacylglycerols and free fatty acids. ATGL's enzymatic activity is co-activated by the protein comparative gene identification-58 (CGI-58) and inhibited by the protein G0/G1 switch gene 2 (G0S2). The enzyme is predicted to act through a catalytic dyad (Ser47, Asp166) located within the conserved patatin domain (Ile10-Leu178). Yet, neither an experimentally determined 3D structure nor a model of ATGL is currently available, which would help to understand how CGI-58 and G0S2 modulate ATGL's activity. In this study we determined the minimal active domain of ATGL. This minimal fragment of ATGL could still be activated and inhibited by CGI-58 and G0S2, respectively. Furthermore, we show that this minimal domain is sufficient for protein-protein interaction of ATGL with its regulatory proteins. Based on these data, we generated a 3D homology model for the minimal domain. It strengthens our experimental finding that amino acids between Leu178 and Leu254 are essential for the formation of a stable protein domain related to the patatin fold. Our data provide insights into the structure-function relationship of ATGL and indicate higher structural similarities in the N-terminal halves of mammalian patatin-like phospholipase domain containing proteins, (PNPLA1, -2,- 3 and -5) than originally anticipated.

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Amino acid sequence alignment of PNPLA family members.The amino acid sequence alignment of mouse PNPLA family members PNPLA1, -2, -3, and -5 shows high sequence conservation at the N-terminal halves of the proteins. Residues at the proposed catalytic sites (oxyanion hole, GXSXG motif, catalytic Asp) are highlighted in yellow. The patatin domain (Ile10-Leu178 for ATGL/PNPLA2) is emphasized in bold red letters. High identity can be also observed in the patatin-related region, up to Leu254 (bold blue).
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pone-0026349-g008: Amino acid sequence alignment of PNPLA family members.The amino acid sequence alignment of mouse PNPLA family members PNPLA1, -2, -3, and -5 shows high sequence conservation at the N-terminal halves of the proteins. Residues at the proposed catalytic sites (oxyanion hole, GXSXG motif, catalytic Asp) are highlighted in yellow. The patatin domain (Ile10-Leu178 for ATGL/PNPLA2) is emphasized in bold red letters. High identity can be also observed in the patatin-related region, up to Leu254 (bold blue).

Mentions: It is also interesting to note, that high sequence identity of ATGL (PNPLA2) with other members of the PNPLA family (PNPLA1, PNPLA3, PNPLA5) continues further than the usually proposed patatin-domain (residue 10–178 in PNPLA2, highlighted in red bold in Figure 8). Mouse PNPLA2 and PNPLA1 share 66% and 67% similarity within residues 10–178 and 5–254, respectively (numbers refer to PNPLA2). Mouse PNPLA2, PNPLA3, and PNPLA5 shares 63% and 60% similarity within residues 10–178 and 5–254, respectively. Interestingly, sequence alignments display larger gaps and a drop in sequence identity after Leu254 (indicated in pink in Figure 8). This could indicate a boundary from a commonly shared domain and the beginning of a separate domain or a Pro-rich linker region. Only few studies on enzymatic activities for the human orthologs of these enzymes are published and report predominantly TG-hydrolyzing activity in addition to low transacylase and phospholipase A2 activity for PNPLA2; TG-hydrolase, transacylase and modest phospholipase A2 activity for PNPLA3. The biochemical functions of PNPLA1 and PNPLA5 are still elusive. These similar activities could be exerted by the well-aligned regions, whereas the remaining C-terminal residues could modulate enzymatic function and substrate specificities of the full-length proteins.


The minimal domain of adipose triglyceride lipase (ATGL) ranges until leucine 254 and can be activated and inhibited by CGI-58 and G0S2, respectively.

Cornaciu I, Boeszoermenyi A, Lindermuth H, Nagy HM, Cerk IK, Ebner C, Salzburger B, Gruber A, Schweiger M, Zechner R, Lass A, Zimmermann R, Oberer M - PLoS ONE (2011)

Amino acid sequence alignment of PNPLA family members.The amino acid sequence alignment of mouse PNPLA family members PNPLA1, -2, -3, and -5 shows high sequence conservation at the N-terminal halves of the proteins. Residues at the proposed catalytic sites (oxyanion hole, GXSXG motif, catalytic Asp) are highlighted in yellow. The patatin domain (Ile10-Leu178 for ATGL/PNPLA2) is emphasized in bold red letters. High identity can be also observed in the patatin-related region, up to Leu254 (bold blue).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198459&req=5

pone-0026349-g008: Amino acid sequence alignment of PNPLA family members.The amino acid sequence alignment of mouse PNPLA family members PNPLA1, -2, -3, and -5 shows high sequence conservation at the N-terminal halves of the proteins. Residues at the proposed catalytic sites (oxyanion hole, GXSXG motif, catalytic Asp) are highlighted in yellow. The patatin domain (Ile10-Leu178 for ATGL/PNPLA2) is emphasized in bold red letters. High identity can be also observed in the patatin-related region, up to Leu254 (bold blue).
Mentions: It is also interesting to note, that high sequence identity of ATGL (PNPLA2) with other members of the PNPLA family (PNPLA1, PNPLA3, PNPLA5) continues further than the usually proposed patatin-domain (residue 10–178 in PNPLA2, highlighted in red bold in Figure 8). Mouse PNPLA2 and PNPLA1 share 66% and 67% similarity within residues 10–178 and 5–254, respectively (numbers refer to PNPLA2). Mouse PNPLA2, PNPLA3, and PNPLA5 shares 63% and 60% similarity within residues 10–178 and 5–254, respectively. Interestingly, sequence alignments display larger gaps and a drop in sequence identity after Leu254 (indicated in pink in Figure 8). This could indicate a boundary from a commonly shared domain and the beginning of a separate domain or a Pro-rich linker region. Only few studies on enzymatic activities for the human orthologs of these enzymes are published and report predominantly TG-hydrolyzing activity in addition to low transacylase and phospholipase A2 activity for PNPLA2; TG-hydrolase, transacylase and modest phospholipase A2 activity for PNPLA3. The biochemical functions of PNPLA1 and PNPLA5 are still elusive. These similar activities could be exerted by the well-aligned regions, whereas the remaining C-terminal residues could modulate enzymatic function and substrate specificities of the full-length proteins.

Bottom Line: Yet, neither an experimentally determined 3D structure nor a model of ATGL is currently available, which would help to understand how CGI-58 and G0S2 modulate ATGL's activity.Based on these data, we generated a 3D homology model for the minimal domain.Our data provide insights into the structure-function relationship of ATGL and indicate higher structural similarities in the N-terminal halves of mammalian patatin-like phospholipase domain containing proteins, (PNPLA1, -2,- 3 and -5) than originally anticipated.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria.

ABSTRACT
Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme of lipolysis. ATGL specifically hydrolyzes triacylglycerols (TGs), thereby generating diacylglycerols and free fatty acids. ATGL's enzymatic activity is co-activated by the protein comparative gene identification-58 (CGI-58) and inhibited by the protein G0/G1 switch gene 2 (G0S2). The enzyme is predicted to act through a catalytic dyad (Ser47, Asp166) located within the conserved patatin domain (Ile10-Leu178). Yet, neither an experimentally determined 3D structure nor a model of ATGL is currently available, which would help to understand how CGI-58 and G0S2 modulate ATGL's activity. In this study we determined the minimal active domain of ATGL. This minimal fragment of ATGL could still be activated and inhibited by CGI-58 and G0S2, respectively. Furthermore, we show that this minimal domain is sufficient for protein-protein interaction of ATGL with its regulatory proteins. Based on these data, we generated a 3D homology model for the minimal domain. It strengthens our experimental finding that amino acids between Leu178 and Leu254 are essential for the formation of a stable protein domain related to the patatin fold. Our data provide insights into the structure-function relationship of ATGL and indicate higher structural similarities in the N-terminal halves of mammalian patatin-like phospholipase domain containing proteins, (PNPLA1, -2,- 3 and -5) than originally anticipated.

Show MeSH
Related in: MedlinePlus