Molecular pathology and therapy in heterogenic and multigenic diseases
Manuel Palacín
Principal Investigator
Professor (Biochemistry and Molecular Biology Dept. - UB)
Office Tel : +34 93 403 71 99
Lab Tel : +34 93 403 47 01/ +34 93 403 71 98/ +34 93 4037197
e-mail : manuel.palacin
irbbarcelona.org
Background
One of the functions of the kidney is the tubular re-absorption of solutes, like amino acids, filtrated in the glomerulus. Several amino acid transporters are involved in this process. Primary inherited aminoacidurias (PIA) are caused by defects in several of these transporters. Over the last ten years studies on PIA have uncovered part of the molecular bases of renal reabsorption of amino acids. The tranporters involved in cystinuria, lysinuric protein intolerance and in most patients with Hartnup disorder have been identified. In contrast, those responsible for isolated cystinuria, autosomal dominant hyperdibasic aminoaciduria type I, isolated lysinuria, renal familial iminoglycinuria, dicarboxylic aminoaciduria and Hartnup disorder in some patients remain elusive.
Heteromeric amino acid transporters (HATs) are composed of a heavy subunit and a light subunit. These are unique features among mammalian plasma membrane amino acid transporters. Two homologous heavy subunits from the SLC3 family have been cloned, rBAT (i.e., related to b0,+ amino acid transport) and 4F2hc (i.e., heavy chain of the surface antigen 4F2hc, also named CD98 or fusion regulatory protein 1 (FRP1). Ten light subunits (SLC7 family members from SLC7A5 to SLC7A14) have been identified. Six of these are partners of 4F2hc (LAT1, LAT2, y+LAT1, y+LAT2, asc1, and xCT); one forms a heterodimer with rBAT (b0,+AT); two (asc2 and AGT-1) appear to interact with as yet unknown heavy subunits; and the last one (arpAT) may interact with rBAT, 4F2hc or an unidentified heavy subunit. Two light subunits are not present in humans: asc2 is not found in the genome sequence and arpAT is heavily inactivated in this genome.
Research Interests
The general objective of our group is to determine the molecular mechanisms involved in renal re-absorption and intestinal absorption of amino acids. This general objective is structured into three levels:
- Identification of the amino acid transporters involved in the re-absorption of amino acids and those responsible for the development of inherited aminoacidurias. Description of the molecular mechanisms underlying the loss of transport functions of the amino acid transporters, due to disease-causing mutations.
- Structural and structure-function relationship studies of Heteromeric Amino Acid Transporters.
- Structure-function relationship studies of the tumorigenic role of the multifunctional protein 4F2hc.
Research Lines
To achieve our objectives, our group is structured around 3 research lines.
1. Identification of the amino acid transporters involved in re-absorption of amino acids and those responsible for the development of inherited aminoacidurias.
Our laboratory reported the seminal observations that led to the identification of a new family of amino acid transporters, the Heteromeric Amino acid Transporters (HATs), with the cloning of rBAT and the functional identification of 4F2hc as ancillary proteins of these transporters. Moreover, we have identified five of the ten light subunits of HATs (b0,+AT, y+LAT1, y+LAT2, LAT2 and ArpAT). Three of these transporters are involved in renal re-absorption of amino acids: i) System b0,+ (rBAT/bo,+AT), responsible for apical re-absorption of dibasic amino acids and cystine. ii) System y+L (4F2hc/y+LAT1), responsible for the basolateral efflux of dibasic amino acids. iii) System L (4F2hc/LAT2), responsible for the basolateral efflux of several neutral amino acids, including cysteine. We have also identified the amino acid transporters that are defective in cystinuria (rBAT/b0,+AT) and lysinuric protein intolerance (4F2hc/y+LAT1). At present, we are studying the physiology of basolateral transporters that are candidates to play a role in renal re-absorption of amino acids and inherited aminoacidurias. Moreover, we are generating mouse models defective in renal re-absorption-related transporters. Indeed, the b0,+AT null knock-out mouse parallels human cystinuria, including cystinuria lithiasis. This model is currently being used to identify new anti-lithiasic drugs.
2. Structural and structure-function relationship studies of Heteromeric Amino Acid Transporters.
We have demonstrated that the light subunit of HATs is the catalytic part of the HAT transporters. Using transporter xCT as a model for the light subunits of HATs, we have delineated the membrane topology of these transporters and identified several relevant residues for their transport activity. Moreover, we have solved the structure of the ectodomain of the heavy chain 4F2hc at a resolution of 2.1 Å. We are currently addressing the atomic structure of HATs by means of several strategies, including the study of prokaryotic homologues of the light subunits.
3. Structure-function relationship studies of the tumorigenic role of the multifunctional protein 4F2hc.
4F2hc (also named CD98) is a multifunctional protein involved in amino acid transport, cell fusion and integrin activation. Moreover, 4F2hc has tumorigenic activity. On the basis of the atomic structure of the ectodomain of this protein, we are currently studying its potential glucosidase and/or lectin activities and also protein interactions of this ectodomain.
Funding
This group receives financial support from the following sources:
- Fundació La Caixa ("La Caixa" Foundation)
- Ministerio de Educación y Ciencia (Spanish Ministry of Science and Education)
- European Commission
- Generalitat de Catalunya (Government of Catalonia)
- Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo (Spanish National Institute of Health)
- Fundació La Marató-TV3 ("La Marató TV3" Foundation)
More info
Molecular pathology and therapy in heterogenic and multigenic diseases
Renal handling of organic solutes
Moe OW, Wright SH and Palacín M
Brenner & Rector's The Kidney (Brenner BM, Ed), Elsevier, 214-247 (2008)
Neuregulins increase mitochondrial oxidative capacity and insulin sensitivity in skeletal muscle cells
Canto C, Pich S, Paz JC, Sanches R, Martinez V, Orpinell M, Palacin M, Zorzano A and Guma A
Diabetes, 56 (9), 2185-2193 (2007)
The structure of human 4F2hc ectodomain provides a model for homodimerization and electrostatic interaction with plasma membrane
Fort J, de la Ballina LR, Burghardt HE, Ferrer-Costa C, Turnay J, Ferrer-Orta C, Usón I, Zorzano A, Fernández-Recio J, Orozco M, Lizarbe MA, Fita I and Palacín M
J Biol Chem, 282 (43), 31444-31452 (2007)
Identification of a novel modulator of thyroid hormone receptor-mediated action
Baumgartner BG, Orpinell M, Duran J, Ribas V, Burghardt HE, Bach D, Villar AV, Paz JC, González M, Camps M, Oriola J, Rivera F, Palacín and Zorzano A
PLoS ONE, 2 (11), e1183 (2007)
Functional and structural characterization of the first prokaryotic member of the L-amino acid transporter (LAT) family: a model for APC transporters
Reig N, del Rio C, Casagrande F, Ratera M, Gelpi JL, Torrents D, Henderson PJ, Xie H, Baldwin SA, Zorzano A, Fotiadis D and Palacin M
J Biol Chem, 282 (18), 13270-13281 (2007)
Oral insulin-mimetic compounds that act independently of insulin
Garcia-Vicente S, Yraola F, Marti L, González-Muñoz E, García-Barrado MJ, Canto C, Abella A, Bour S, Artuch R, Sierra C, Brandi N, Carpene C, Moratinos J, Camps M, Palacín M, Testar X, Guma A, Albericio F, Royo M, Mian A and Zorzano A
Diabetes, 56 (2), 486-493 (2007)
Myotonia-related mutations in the distal C-terminus of ClC-1 and ClC-0 chloride channels affect the structure of a poly-proline helix
Macías MJ, Teijido O, Zifarelli G, Martin P, Ramirez-Espain X, Zorzano A, Palacín M, Pusch M and Estévez R
Biochem J, 403 (1), 79-87 (2007)
Expression patterns of MLC1 protein in the central and peripheral nervous systems
Teijido O, Casaroli-Marano R, Kharkovets T, Aguado F, Zorzano A, Palacín M, Soriano E, Martínez A and Estévez R
Neurobiol Dis, 26 (3), 532-545 (2007)
Role of myotonic dystrophy protein kinase (DMPK) in glucose homeostasis and muscle insulin action
Llagostera E, Catalucci D, Marti L, Liesa M, Camps M, Ciaraldi TP, Kondo R, Reddy S, Dillmann WH, Palacin M, Zorzano A, Ruiz-Lozano P, Gomis R and Kaliman P
PLoS ONE, 2 (11), e1134 (2007)
Slc7a9 knockout mouse is a good cystinuria model for antilithiasic pharmacological studies
Font-Llitjós M, Feliubadaló L, Espino M, Clèries R, Mañas S, Frey IM, Puertas S, Colell G, Palomo S, Aranda J, Visa J, Palacín M, Nunes V
Am J Physiol Renal Physiol, 293 (3), :F732-40. Epub-PMID: 17596531 [PubMed - indexed for MEDLINE] (2007)
The structural and functional units of heteromeric amino acid transporters. The heavy subunit rBAT dictates oligomerization of the heteromeric amino acid transporters
Fernández E, Jiménez-Vidal M, Calvo M, Zorzano A, Tebar F, Palacín M and Chillaron J
J Biol Chem, 281 (36), 26552-26561 (2006)
Arginine transport via cationic amino acid transporter 2 plays a critical regulatory role in classical or alternative activation of macrophages
Yeramian A, Martín L, Serrat N, Arpa L, Soler C, Bertran J, McLeod C, Palacín M, Modolell M, Lloberas J and Celada A
J Immunol, 176 (10), 5918-5924 (2006)
Granulocyte-macrophage colony-stimulating factor increases L-arginine transport through the induction of CAT2 in bone marrow-derived macrophages
Martin L, Comalada M, Marti L, Closs EI, Macleod CL, Martin Del Rio R, Zorzano A, Modolell M, Celada A, Palacin M and Bertran J
Am J Physiol Cell Physiol, 290 (5), C1364-1372 (2006)
Evidence for a mitochondrial regulatory pathway defined by peroxisome proliferator-activated receptor-gamma coactivator-1 alpha, estrogen-related receptor-alpha, and mitofusin 2
Soriano FX, Liesa M, Bach D, Chan DC, Palacín M and Zorzano A
Diabetes, 55 (6), 1783-1791 (2006)
Macrophages require distinct arginine catabolism and transport systems for proliferation and for activation
Yeramian A, Martin L, Arpa L, Bertran J, Soler C, McLeod C, Modolell M, Palacin M, Lloberas J and Celada A
Eur J Immunol, 36 (6), 1516-1526 (2006)
Vacuolating megalencephalic leukoencephalopathy with subcortical cysts: functional studies of novel variants in MLC1
Montagna G, Teijido O, Eymard-Pierre E, Muraki K, Cohen B, Loizzo A, Grosso P, Tedeschi G, Palacin M, Boespflug-Tanguy O, Bertini E, Santorelli FM and Estevez R
Hum Mutat, 27 (3), 292 (2006)
Neuregulins mediate calcium-induced glucose transport during muscle contraction
Canto C, Chibalin AV, Barnes BR, Glund S, Suarez E, Ryder JW, Palacín M, Zierath JR, Zorzano A and Guma A
J Biol Chem, 28 (31), 21690-21697 (2006)
y+ LAT-1 mediates transport of the potent and selective iNOS inhibitor, GW274150, in control J774 macrophages
Baydoun AR, Bertran J, Thakur S, Dawson J, Palacín M, and Knowles RG
Amino Acids, 31 (2), 101-109 (2006)
T3 strongly regulates GLUT1 and GLUT3 mRNA in cerebral cortex of hypothyroid rat neonates
Santalucia T, Palacín M and Zorzano A
Mol Cell Endocrinol, 251 (1-2), 9-16 (2006)
Expression of Mfn2, the Charcot-Marie-Tooth neuropathy type 2A gene, in human skeletal muscle: effects of type 2 diabetes, obesity, weight loss, and the regulatory role of tumor necrosis factor alpha and interleukin-6
Bach D, Naon D, Pich S, Soriano FX, Vega N, Rieusset J, Laville M, Guillet C, Boirie Y, Wallberg-Henriksson H, Manco M, Calvani M, Castagneto M, Palacin M, Mingrone G, Zierath JR, Vidal H and Zorzano A
Diabetes, 54 (9), 2685-2693 (2005)
Identification and functional characterization of a novel low affinity aromatic-preferring amino acid transporter (arpAT) One of the few proteins silenced during primate evolution
Fernandez E, Torrents D, Zorzano A, Palacin M and Chillaron J
J Biol Chem, 280 (19), 19364-19372 (2005)
Identification of LAT4, a novel amino acid transporter with system L activity
Bodoy S, Martin L, Zorzano A, Palacin M, Estevez R and Bertran J
J Biol Chem, 280 (12), 12002-12011 (2005)
The release of soluble VAP-1/SSAO by 3T3-L1 adipocytes is stimulated by isoproterenol and low concentrations of TNFalpha
Garcia-Vicente S, Abella A, Viguerie N, Ros-Baro A, Camps M, Testar X, Palacin M, Zorzano A and Marti L
J Physiol Biochem, 61 (2), 395-401 (2005)
The Charcot-Marie-Tooth type 2A gene product, Mfn2, up-regulates fuel oxidation through expression of OXPHOS system
Pich S, Bach D, Briones P, Liesa M, Camps M, Testar X, Palacín M and Zorzano A
Human Mol Genet, 14 (11), 1405-1415 (2005)
Mechanisms regulating GLUT4 glucose transporter expression and glucose transport in skeletal muscle
Zorzano A, Palacin M and Guma A
Acta Physiol Scand, 183 (1), 43-58 (2005)
The genetics of heteromeric amino acid transporters
Palacin M, Nunes V, Font-Llitjos M, Jimenez-Vidal M, Fort J, Gasol E, Pineda M, Feliubadalo L, Chillaron J and Zorzano A
Physiology (Bethesda), 20, 112-124 (2005)
Neutral amino acid transport mediated by ortholog of imino acid transporter SIT1/SLC6A20 in opossum kidney cells
Ristic Z, Camargo SM, Romeo E, Bodoy S, Bertran J, Palacin M, Makrides V, Furrer EM and Verrey F
Am J Physiol Renal Physiol, 18 (4) (2005)
Studies on the function of TM20, a transmembrane protein present in cereal embryos
Jahrmann T, Bastida M, Pineda M, Gasol E, Ludevid MD, Palacin M, Puigdomenech P
Planta, 222 (1), 80-90 (2005)
New insights into cystinuria: 40 new mutations, genotype-phenotype correlation, and digenic inheritance causing partial phenotype
Font-Llitjos M, Jimenez-Vidal M, Bisceglia L, Di Perna M, de Sanctis L, Rousaud F, Zelante L, Palacin M and Nunes V
J Med Genet, 42 (1), 58-68 (2005)
Exploring the binding mode of semicarbazide-sensitive amine oxidase/VAP-1: identification of novel substrates with insulin-like activity
Marti L, Abella A, De La Cruz X, García-Vicente S, Unzeta M, Carpéné C, Palacín M, Testar X, Orozco M and Zorzano A
J Med Chem, 47 (20), 4865-4874 (2004)
The amino acid transporter asc-1 is not involved in cystinuria
Pineda M, Font M, Bassi MT, Manzoni M, Borsani G, Marigo V, Fernandez E, Rio RM, Purroy J, Zorzano A, Nunes V and Palacin M
Kidney Int, 66 (4), 1453-1464 (2004)
Localization and functional analyses of the MLC1 protein involved in megalencephalic leukoencephalopathy with subcortical cysts
Teijido O, Martinez A, Pusch M, Zorzano A, Soriano E, Del Rio JA, Palacin M and Estevez R
Hum Mol Genet, 13 (21), 2581-2594 (2004)
Adipocytes release a soluble form of VAP-1/SSAO by a metalloprotease-dependent process and in a regulated manner
Abella A, Garcia-Vicente S, Viguerie N, Ros-Baro A, Camps M, Palacin M, Zorzano A and Marti L
Diabetologia, 47 (3), 429-438 (2004)
A novel muscle DNA-binding activity in the GLUT1 promoter
Sanchez-Feutrie M, Santalucia T, Fandos C, Noe V, Vinals F, Brand NJ, Ciudad CJ, Palacin M and Zorzano A
Cell Mol Life Sci, 61 (6), 709-720 (2004)
Myotonic dystrophy protein kinase phosphorylates phospholamban and regulates calcium uptake in cardiomyocyte sarcoplasmic reticulum
Kaliman P, Catalucci D, Lam JT, Kondo R, Gutierrez JC, Reddy S, Palacin M, Zorzano A, Chien KR and Ruiz-Lozano P
J Biol Chem, 280 (9), 8016-8021 (2004)
Thiol modification of cysteine 327 in the eighth transmembrane domain of the light subunit xCT of the heteromeric cystine/glutamate antiporter suggests close proximity to the substrate binding site/permeation pathway
Jimenez-Vidal M, Gasol E, Zorzano A, Nunes V, Palacin M and Chillaron J
J Biol Chem, 279 (12), 11214-11221 (2004)
Neuregulin signaling on glucose transport in muscle cells
Cantó C, Suárez E, Lizcano J, Griñó E, Shepherd P, Fryer L, Carling D, Bertran J, Palacin M, Zorzano A and Gumà A
J Biol Chem, 279 (13), 12260-12268 (2004)
Membrane topology of system xc- light subunit reveals a re-entrant loop with substrate-restricted accessibility
Gasol E, Jiménez-Vidal M, Chillarón J, Zorzano A and Palacín M
J Biol Chem, 279 (30), 31228-31236 (2004)
CATs and HATs: the SLC7 family of amino acid transporters
Verrey F, Closs EI, Wagner CA, Palacin M, Endou H and Kanai Y
Pflugers Arch., 447 (5), 532-542 (2004)
The ancillary proteins of HATs: SLC3 family of amino acid transporters
Palacin M and Kanai Y
Pflugers Arch, 447 (5), 490-494 (2004)
Cystinuria-specific rBAT(R365W) mutation reveals two translocation pathways in the amino acid transporter rBAT-b0,+AT
Pineda M, Wagner CA, Broer A, Stehberger PA, Kaltenbach S, Gelpi JL, Martin Del Rio R, Zorzano A, Palacin M, Lang F and Broer S
Biochem J, 377 (Pt 3), 665-674 (2004)
Lysinuric protein intolerance: mechanisms of pathophysiology
Palacin M, Bertran J, Chillaron J, Estevez R and Zorzano A
Mol Genet Metab, 81 (Suppl 1), 27-37 (2004)
Thiol modification of cysteine 327 in the eighth transmembrane domain of the light subunit xCT of the heteromeric cystine/glutamate antiporter suggests close proximity to the substrate binding site/permeation pathway
Jimenez-Vidal M, Gasol E, Zorzano A, Nunes V, Palacin M and Chillaron J
J Biol Chem, 279 (12), 11214-11221 (2004)
Slc7a9-deficient mice develop cystinuria non-I and cystine urolithiasis
Feliubadalo L, Arbones ML, Manas S, Chillaron J, Visa J, Rodes M, Rousaud F, Zorzano A, Palacin M and Nunes V
Hum Mol Genet, 12 (17), 2097-2108 (2003)
Differential regulation of the muscle-specific GLUT4 enhancer in regenerating and adult skeletal muscle
Moreno H, Serrano AL, Santalucia T, Guma A, Canto C, Brand NJ, Palacin M, Schiaffino S and Zorzano A
J Biol Chem, 278 (42), 40557-40564 (2003)
Mitofusin-2 determines mitochondrial network architecture and mitochondrial metabolism. A novel regulatory mechanism altered in obesity
Bach D, Pich S, Soriano FX, Vega N, Baumgartner B, Oriola J, Daugaard JR, Lloberas J, Camps M, Zierath JR, Rabasa-Lhoret R, Wallberg-Henriksson H, Laville M, Palacín M, Vidal H, Rivera F, Brand M and Zorzano A
J Biol Chem, 278 (19), 17190-17197 (2003)
Intracellular signals involved in the effects of insulin-like growth factors and neuregulins on myofibre formation
Zorzano A, Kaliman P, Gumà A and Palacín M
Cell Signal, 15 (2), 141-149 (2003)
Identification of a novel proliferation-dependent C-rich element that mediates inhibition of the rat GLUT1 promoter
Sánchez-Feutrie M, Viñals F, Palacín M and Zorzano A
Gene, 322, 47-55 (2003)
Semicarbazide-sensitive amine oxidase/vascular adhesion protein-1 activity exerts an antidiabetic action in Goto-Kakizaki rats
Abella A, Marti L, Camps M, Claret M, Fernández-Alvarez J, Gomis R, Gumà A, Viguerie N, Carpéné C, Palacín M, Testar X and Zorzano A
Diabetes, 52 (4), 1004-1013 (2003)
Semicarbazide-sensitive amine oxidase activity exerts insulin-like effects on glucose metabolism and insulin-signaling pathways in adipose cells
Zorzano A, Abella A, Marti L, Carpéné C, Palacín M and Testar X
Biochim Biophys Acta, 1647 (1-2), 3-9 (2003)
Basolateral LAT-2 has a major role in the transepithelial flux of L-cystine in the renal proximal tubule cell line OK
Fernandez E, Torrents D, Chillaron J, Martin Del Rio R, Zorzano A and Palacin M
J Am Soc Nephrol, 14 (4), 837-847 (2003)
Stimulation of glucose transport by semicarbazide-sensitive amine oxidase activity in adipocytes from diabetic rats
Abella A, Marti L, Carpene C, Palacin M, Testar X and Zorzano A
J Physiol Biochem, 59 (3), 153-60 (2003)
