scholarly journals LP2, a differentiation-associated lipid-binding protein expressed in bovine lens

1996 ◽  
Vol 320 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Cynthia JAWORSKI ◽  
Graeme WISTOW
Keyword(s):  
Cellular Differentiation ◽  
Expression Patterns ◽  
Complete Sequence ◽  
Lipid Binding ◽  
Human Lens ◽  
Fatty Acid Binding Proteins ◽  
Lens Protein ◽  
Differentiation Markers ◽  
Fatty Acid Binding ◽  
Bovine Lens

A 13 kDa protein from bovine lens was identified and characterized by protein microsequencing and by rapid amplification of cDNA ends (RACE) PCR. Its complete sequence shows that this protein belongs to a family of fatty acid-binding proteins (FABPs), including myelin and adipocyte P2, that are associated with cellular differentiation. The bovine lens protein, designated LP2, shows very close similarity to human epidermal FABP (eFABP) and human eFABP was detected in human lens, suggesting that the two proteins might be orthologous. Reverse transcriptase–PCR (RT–PCR) was used to compare expression patterns of LP2 with those for actin and for the differentiation markers γB-crystallin and γs-crystallin in lens. Actin was most abundant in the relatively undifferentiated epithelial cells and decreased with lens cell differentiation. In contrast γB-crystallin and γs-crystallin were detected only in fibres (nuclear and cortical respectively). LP2 transcripts were detected most abundantly in fibre cells and apparently increased with cellular differentiation. Molecular modelling confirms that the sequence of LP2 fits the tertiary template of adipocyte P2 but reveals the presence of two close pairs of cysteine residues that might be susceptible to intramolecular disulphide bond formation under appropriate oxidizing conditions. LP2 is thus another potential target for oxidative stress during cataract formation in lens.

scholarly journals The Role of Intestinal Fatty Acid Binding Proteins in Protecting Cells from Fatty Acid Induced Impairment of Mitochondrial Dynamics and Apoptosis

2018 ◽  
Vol 51 (4) ◽  
pp. 1658-1678 ◽  
Author(s):  
Suparna Sarkar-Banerjee ◽  
Sourav Chowdhury ◽  
Dwipanjan Sanyal ◽  
Tulika Mitra ◽  
Sib Sankar Roy ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Binding Proteins ◽  
Apoptotic Cell ◽  
Mitochondrial Dynamics ◽  
Ectopic Expression ◽  
Lipid Binding ◽  
Confocal Imaging ◽  
Fatty Acid Binding Proteins ◽  
Mitochondrial Morphology ◽  
Fatty Acid Binding

Background/Aims: The conformation, folding and lipid binding properties of the intestinal fatty acid binding proteins (IFABP) have been extensively investigated. In contrast, the functional aspects of these proteins are not understood and matter of debates. In this study, we aim to address the deleterious effects of FA overload on cellular components, particularly mitochondria; and how IFABP helps in combating this stress by restoring the mitochondrial dynamics. Methods: In the present study the functional aspect of IFABP under conditions of lipid stress was studied by a string of extensive in-cell studies; flow cytometry by fluorescence-activated cell sorting (FACS), confocal imaging, western blotting and quantitative real time PCR. We deployed ectopic expression of IFABP in rescuing cells under the condition of lipid stress. Again in order to unveil the mechanistic insights of functional traits, we arrayed extensive computational approaches by means of studying centrality calculations along with protein-protein association and ligand induced cluster dissociation. While addressing its functional importance, we used FCS and in-silico computational analyses, to show the structural distribution and the underlying mechanism of IFABP’s action. Results: Ectopic expression of IFABP in HeLa cells has been found to rescue mitochondrial morphological dynamics and restore membrane potential, partially preventing apoptotic damage induced by the increased FAs. These findings have been further validated in the functionally relevant intestinal Caco-2 cells, where the native expression of IFABP protects mitochondrial morphology from abrogation induced by FA overload. However, this native level expression is insufficient to protect against apoptotic cell death, which is rescued, at least partially in cells overexpressing IFABP. In addition, shRNA mediated IFABP knockdown in Caco-2 cells compromises mitochondrial dynamics and switches on intrinsic apoptotic pathways under FA-induced metabolic stress. Conclusion: To summarize, the present study implicates functional significance of IFABP in controlling ligand-induced damage in mitochondrial dynamics and apoptosis.

scholarly journals Fat depot origin affects fatty acid handling in cultured rat and human preadipocytes

2001 ◽  
Vol 280 (2) ◽  
pp. E238-E247 ◽  
Author(s):  
Frank Caserta ◽  
Tamara Tchkonia ◽  
Vildan N. Civelek ◽  
Marc Prentki ◽  
Nicholas F. Brown ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Binding Protein ◽  
Lipid Binding ◽  
Fatty Acid Binding Proteins ◽  
Fatty Acid Binding ◽  
Chain Acyl ◽  
Human Preadipocytes ◽  
Fat Depot ◽  
Carnitine Palmitoyltransferase 1 ◽  
Adipose Cells

Regional differences in free fatty acid (FFA) handling contribute to diseases associated with particular fat distributions. As cultured rat preadipocytes became differentiated, FFA transfer into preadipocytes increased and was more rapid in single perirenal than in epididymal cells matched for lipid content. Uptake by human omental preadipocytes was greater than uptake by abdominal subcutaneous preadipocytes. Adipose-specific fatty acid binding protein (aP2) and keratinocyte lipid binding protein abundance was higher in differentiated rat perirenal than in epididymal preadipocytes. This interdepot difference in preadipocyte aP2 expression was reflected in fat tissue in older animals. Carnitine palmitoyltransferase 1 activity increased during differentiation and was higher in perirenal than in epididymal preadipocytes, particularly the muscle isoform. Long-chain acyl-CoA levels were higher in perirenal than in epididymal preadipocytes and isolated fat cells. These data are consistent with interdepot differences in fatty acid flux ensuing from differences in fatty acid binding proteins and enzymes of fat metabolism. Heterogeneity among depots results, in part, from distinct intrinsic characteristics of adipose cells. Different depots are effectively separate miniorgans.

scholarly journals Selective Cooperation between Fatty Acid Binding Proteins and Peroxisome Proliferator-Activated Receptors in Regulating Transcription

2002 ◽  
Vol 22 (14) ◽  
pp. 5114-5127 ◽  
Author(s):  
Nguan-Soon Tan ◽  
Natacha S. Shaw ◽  
Nicolas Vinckenbosch ◽  
Peng Liu ◽  
Rubina Yasmin ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Fatty Acid ◽  
Binding Proteins ◽  
Lipid Binding ◽  
Fatty Acid Binding Proteins ◽  
Peroxisome Proliferator ◽  
Fatty Acid Binding ◽  
Peroxisome Proliferator Activated Receptors ◽  
Retinoic Acid Binding Proteins ◽  
Crabp Ii

ABSTRACT Lipophilic compounds such as retinoic acid and long-chain fatty acids regulate gene transcription by activating nuclear receptors such as retinoic acid receptors (RARs) and peroxisome proliferator-activated receptors (PPARs). These compounds also bind in cells to members of the family of intracellular lipid binding proteins, which includes cellular retinoic acid-binding proteins (CRABPs) and fatty acid binding proteins (FABPs). We previously reported that CRABP-II enhances the transcriptional activity of RAR by directly targeting retinoic acid to the receptor. Here, potential functional cooperation between FABPs and PPARs in regulating the transcriptional activities of their common ligands was investigated. We show that adipocyte FABP and keratinocyte FABP (A-FABP and K-FABP, respectively) selectively enhance the activities of PPARγ and PPARβ, respectively, and that these FABPs massively relocate to the nucleus in response to selective ligands for the PPAR isotype which they activate. We show further that A-FABP and K-FABP interact directly with PPARγ and PPARβ and that they do so in a receptor- and ligand-selective manner. Finally, the data demonstrate that the presence of high levels of K-FABP in keratinocytes is essential for PPARβ-mediated induction of differentiation of these cells. Taken together, the data establish that A-FABP and K-FABP govern the transcriptional activities of their ligands by targeting them to cognate PPARs in the nucleus, thereby enabling PPARs to exert their biological functions.

scholarly journals How does seminal plasma fatty-acid binding protein-9 level change in infertile males?

2020 ◽  
Vol 107 (3) ◽  
pp. 419-430
Author(s):  
E. Menevse ◽  
R. Sevinc ◽  
D. Dursunoglu ◽  
N. Akdam ◽  
E.N. Korucu
Keyword(s):  
Fatty Acid ◽  
Seminal Plasma ◽  
Sperm Count ◽  
Binding Protein ◽  
Sperm Concentration ◽  
Lipid Binding ◽  
Semen Parameters ◽  
Fatty Acid Binding Proteins ◽  
Specific Expression ◽  
Fatty Acid Binding

AbstractIn recent years, free fatty acid binding proteins (FABPs) are implicated in spermatogenesis and sperm morphology. FABPs are members of the intracellular lipid-binding protein family; they exhibit tissue specific expression like the FABP9/PERF15 (Perforated15) male germ cell-specific fatty acid linkage-protein.The aim of the study was to assess the levels of seminal FABP-9 in normozoospermic and oligozoospermic men, and the possible relations between seminal FABP-9 levels and semen parameters.Research was carried out on 60 male volunteers who were admitted to Selcuk University Faculty of Medicine of Andrology Laboratory. Normozoospermic individuals (n = 30) were identified as Group 1, and Oligozoospermic individuals (n = 30) were identified as Group 2. The semen samples were collected in sterile plastic containers. Sperm parameters were assessed according to Kruger's criteria. Seminal plasma FABP-9 levels were analyzed by ELISA method. Outcomes were statistically evaluated at 0.05 significance level with SPSS (22.0). The Receiver Operating Characteristic (ROC) curve was used to evaluate the performance of FABP-9 levels as compared to that of the concentration and motility data of the sperm. FABP-9 levels were significantly higher in normozoospermic individuals (3.41 ± 1.64 ng/mL) than in oligozoospermic individuals (1.99 ± 0.78 ng/mL). There were significant correlations between FABP-9 levels and sperm concentration, total sperm count, motility, progressive motility, immobility, Total Progressive Motil Sperm Count (TPMSC), head anomaly, and teratozoospermia index.We suggest that FABP-9 level is an important biomarker, and low levels of semen FABP-9 may impact the fertility status based on the ROC findings.

scholarly journals Ligand Entry into Fatty Acid Binding Protein via Local Unfolding instead of Gap Widening

2019 ◽  
Author(s):  
T Xiao ◽  
Y Lu ◽  
J Fan ◽  
D Yang
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Binding Proteins ◽  
Lipid Binding ◽  
Relaxation Dispersion ◽  
Chemical Exchange Saturation Transfer ◽  
Fatty Acid Binding Proteins ◽  
Fatty Acid Binding ◽  
Protein Cavity ◽  
Local Unfolding

AbstractFatty acid binding proteins (FABPs) play an important role in transportation of fatty acids. Despite intensive studies, how fatty acids enter the protein cavity for binding is still controversial. Here, a gap-closed variant of human intestinal FABP was generated by mutagenesis, in which the gap is locked by a disulfide bridge. According to its structure determined here by NMR, this variant has no obvious openings as the ligand entrance and the gap cannot be widened by internal dynamics. Nevertheless, it still uptakes fatty acids and other ligands. NMR relaxation dispersion, chemical exchange saturation transfer and hydrogen-deuterium exchange experiments show that the variant exists in a major native state, two minor native-like state, and two locally unfolded states in aqueous solution. Local unfolding of either βB–βD or helix 2 can generate an opening large enough for ligands to enter the protein cavity, but only the fast local unfolding of helix 2 is relevant to the ligand entry process.Statement of SignificanceFatty acid binding proteins transport fatty acids to specific organelles in the cell. To enable the transport, fatty acids must enter and leave the protein cavity. In spite of many studies, how fatty acids enter the protein cavity remains controversial. Using mutagenesis and biophysical techniques, we have resolved the disagreement and further showed that local unfolding of the second helix can generate a transient opening to allow ligands to enter the protein cavity. Since lipid binding proteins are highly conserved in 3D structures and ligand binding, all of them may use the same local unfolding mechanism for ligand uptake and release.

scholarly journals Functional analysis of peroxisome-proliferator-responsive element motifs in genes of fatty acid-binding proteins

2004 ◽  
Vol 382 (1) ◽  
pp. 239-245 ◽  
Author(s):  
Christian SCHACHTRUP ◽  
Tanja EMMLER ◽  
Bertram BLECK ◽  
Anton SANDQVIST ◽  
Friedrich SPENER
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Binding Proteins ◽  
Lipid Binding ◽  
Fatty Acid Binding Proteins ◽  
Computer Search ◽  
Peroxisome Proliferator ◽  
Fatty Acid Binding ◽  
Responsive Element

Retinoic acids and long-chain fatty acids are lipophilic agonists of nuclear receptors such as RXRs (retinoic X receptors) and PPARs (peroxisome-proliferator-activated receptors) respectively. These agonists are also ligands of intracellular lipid-binding proteins, which include FABPs (fatty acid-binding proteins). We reported previously that L (liver-type)-FABP targets fatty acids to the nucleus of hepatocytes and affects PPARα activation, which binds together with an RXR subtype to a PPRE (peroxisome-proliferator-responsive element). In the present study, we first determined the optimal combination of murine PPAR/RXR subtypes for binding to known murine FABP-PPREs and to those found by computer search and then tested their in vitro functionality. We show that all PPARs bind to L-FABP-PPRE, PPARα, PPARγ1 and PPARγ2 to A (adipocyte-type)-FABP-PPRE. All PPAR/RXR heterodimers transactivate L-FABP-PPRE, best are combinations of PPARα with RXRα or RXRγ. In contrast, PPARα heterodimers do not transactivate A-FABP-PPRE, best combinations are of PPARγ1 with RXRα and RXRγ, and of PPARγ2 with all RXR subtypes. We found that the predicted E (epidermal-type)- and H (heart-type)-FABP-PPREs are not activated by any PPAR/RXR combination without or with the PPAR pan-agonist bezafibrate. In the same way, C2C12 myoblasts transfected with promoter fragments of E-FABP and H-FABP genes containing putative PPREs are also not activated through stimulation of PPARs with bezafibrate applied to the cells. These results demonstrate that only PPREs of L- and A-FABP promoters are functional, and that binding of PPAR/RXR heterodimers to a PPRE in vitro does not necessarily predict transactivation.

scholarly journals Crystal structure of zinc-α2-glycoprotein in complex with a fatty acid reveals multiple different modes of protein-lipid binding

2019 ◽  
Vol 476 (19) ◽  
pp. 2815-2834 ◽  
Author(s):  
Andy M. Lau ◽  
Henna Zahid ◽  
Jayesh Gor ◽  
Stephen J. Perkins ◽  
Alun R. Coker ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Conformational Changes ◽  
Analytical Ultracentrifugation ◽  
Binding Capacity ◽  
Lipid Binding ◽  
Fatty Acid Binding Proteins ◽  
Fatty Acid Binding ◽  
Carboxylate Groups

Abstract Human zinc-α2-glycoprotein (ZAG) is a 42 kDa adipokine which regulates body fat mass and is associated with cachexia and obesity. ZAG belongs to the major histocompatibility complex class I protein family and binds long-chain polyunsaturated fatty acids in its groove formed from the α1 and α2 domains. To identify the molecular basis of its lipid-binding function, we determined the first crystal structure at 2.49 Å resolution for fatty acid-bound ZAG, where the ligand was the fluorescent 11-(dansylamino)undecanoic acid (DAUDA). The 192 kDa crystallographic asymmetric unit contained six ZAG and eight fatty acid molecules in unique conformations. Six fatty acid molecules were localised to the ZAG grooves, where their tails were bound in two distinct conformations. The carboxylate groups of three fatty acids projected out of the groove, while the fourth was hydrogen bonded with R73 inside the groove. Other ligand-residue contacts were primarily hydrophobic. A new fatty acid site was revealed for two further DAUDA molecules at the ZAG α3 domains. Following conformational changes from unbound ZAG, the α3 domains formed tetrameric β-barrel structures lined by fatty acid molecules that doubled the binding capacity of ZAG. Analytical ultracentrifugation revealed that ZAG in solution was a monomer in the absence of DAUDA, but formed small amounts of tetramers with DAUDA. By showing that ZAG binds fatty acids in different locations, we demonstrate an augmented mechanism for fatty acid binding in ZAG that is distinct from other known fatty acid binding proteins, and may be relevant to cachexia.

Sign in / Sign up

Export Citation Format

Share Document