Microtubule-Associated Protein 1B Function during Normal Development, Regeneration, and Pathological Conditions in the Nervous System

Journal of Neurobiology

Volumn 58, Issue 1, 2004, Pages 48-59

  Gonzalez Billault, Christian ^a,b   Jimenez Mateos, Eva Maria ^a   Caceres, Alfredo ^c   Diaz Nido, Javier ^a   Wandosell, Francisco ^a   Avila, Jesus ^a  

^a CENTRO DE BIOLOGÍA MOLECULAR SEVERO OCHOA   (Spain)

^b UNIVERSITY OF CHILE   (Chile)

^c INSTITUTO DE INVESTIGACIÓN MÉDICA MERCEDES Y MARTÍN FERREYRA   (Argentina)

Author keywords

Axonogenesis; MAP1B; Mutants; Phosphorylation

Indexed keywords

MICROTUBULE ASSOCIATED PROTEIN 5;

ALZHEIMER DISEASE; DYNAMICS; MICROFILAMENT; MICROTUBULE; MOLECULAR MODEL; NERVE FIBER REGENERATION; NERVE REGENERATION; NERVOUS SYSTEM DEVELOPMENT; NEUROFIBRILLARY TANGLE; NEUROLOGIC DISEASE; NEUROPATHY; NONHUMAN; POLYMERIZATION; PRIORITY JOURNAL; PROTEIN EXPRESSION; PROTEIN FUNCTION; PROTEIN PHOSPHORYLATION; REVIEW;

ANIMALS; HUMANS; MICROTUBULE-ASSOCIATED PROTEINS; NERVE REGENERATION; NERVOUS SYSTEM; NERVOUS SYSTEM DISEASES; NERVOUS SYSTEM PHYSIOLOGY;

EID: 0346750742     PISSN: 00223034     EISSN: None     Source Type: Journal    
DOI: 10.1002/neu.10283     Document Type: Review

References (104)

1. Avila J, Ulloa L, Diez-Guerra J, Diaz-Nido J. 1994a. Role of phosphorylated MAP1B in neuritogenesis. Cell Biol Int 18:309-314.
2. Avila J, Ulloa L, Gonzalez J, Moreno F, Diaz-Nido J. 1994b. Phosphorylation of microtubule-associated proteins by protein kinase CK2 in neuritogenesis. Cell Mol Biol Res 40:573-579.
3. Bates CA, Trinh N, Meyer RL. 1993. Distribution of microtubule-associated proteins (MAPs) in adult and embryonic mouse retinal explants: presence of the embryonic map, MAPS/1B, in regenerating adult retinal axons. Dev Biol 155:533-544.
4. Binder LI, Frankfurter A, Kim H, Caceres A, Payne MR, Rebhun LI. 1984. Heterogeneity of microtubule-associated protein 2 during rat brain development. Proc Natl Acad Sci USA 81:5613-5617.
5. Black MM, Slaughter T, Fischer I. 1994. Microtubule-associated protein 1b (MAP1b) is concentrated in the distal region of growing axons. J Neurosci 14:857-870.
6. Bloom GS, Luca FC, Vallee RB. 1985. Microtubule-associated protein 1B: identification of a major component of the neuronal cytoskeleton. Proc Natl Acad Sci USA 82:5404-5408.
7. Bomont P, Cavalier L, Blondeau F, Ben Hamida C, Belal S, Tazir M, Demir E, Topaloglu H, Korinthenberg R, Tuysuz B, et al. 2000. The gene encoding gigaxonin, a new member of the cytoskeletal BTB/kelch repeat family, is mutated in giant axonal neuropathy. Nat Genet 26:370-374.
8. Book AA, Fischer I, Yu XJ, Iannuzzelli P, Murphy EH. 1996. Altered expression of microtubule-associated proteins in cat trochlear motoneurons after peripheral and central lesions of the trochlear nerve. Exp Neurol 138:214-226.
9. Brugg B, Reddy D, Matus A. 1993. Attenuation of microtubule-associated protein 1B expression by antisense oligodeoxynucleotides inhibits initiation of neurite outgrowth. Neuroscience 52:489-496.
10. Bush MS, Goold RG, Moya F, Gordon-Weeks PR. 1996a. An analysis of an axonal gradient of phosphorylated MAP 1B in cultured rat sensory neurons. Eur J Neurosci 8:235-248.
11. Bush MS, Tonge DA, Woolf C, Gordon-Weeks PR. 1996b. Expression of a developmentally regulated, phosphorylated isoform of microtubule-associated protein 1B in regenerating axons of the sciatic nerve. Neuroscience 73:553-563.
12. Calvert R, Anderton BH. 1985. A microtubule-associated protein (MAP1) which is expressed at elevated levels during development of the rat cerebellum. Embo J 4:1171-1176.
13. Cheng A, Krueger BK, Bambrick LL. 1999. MAP5 expression in proliferating neuroblasts. Brain Res Dev Brain Res 113:107-113.
14. Chowdhury K, Bonaldo P, Torres M, Stoykova A, Gruss P. 1997. Evidence for the stochastic integration of gene trap vectors into the mouse germline. Nucleic Acids Res 25:1531-1536.
15. Crino PB, Trojanowski JQ, Eberwine J. 1997. Internexin, MAP1B, and nestin in cortical dysplasia as markers of developmental maturity. Acta Neuropathol (Berl) 93:619-627.
16. Diaz-Nido J, Armas-Portela R, Correas I, Dominguez JE, Montejo E, Avila J. 1991. Microtubule protein phosphorylation in neuroblastoma cells and neurite growth. J Cell Sci Suppl 15:51-59.
17. Diaz-Nido J, Avila J. 1989. Characterization of proteins immunologically related to brain microtubule-associated protein MAP-1B in non-neural cells. J Cell Sci 92(Pt 4):607-620.
18. Diaz-Nido J, Serrano L, Hernandez MA, Avila J. 1990. Phosphorylation of microtubule proteins in rat brain at different developmental stages: comparison with that found in neuronal cultures. J Neurochem 54:211-222.
19. Diaz-Nido J, Serrano L, Mendez E, Avila J. 1988. A casein kinase II-related activity is involved in phosphorylation of microtubule-associated protein MAP-1B during neuroblastoma cell differentiation. J Cell Biol 106:2057-2065.
20. Ding J, Liu JJ, Kowal AS, Nardine T, Bhattacharya P, Lee A, Yang Y. 2002. Microtubule-associated protein 1B: a neuronal binding partner for gigaxonin. J Cell Biol 158:427-433.
21. DiTella MC, Feiguin F, Carri N, Kosik KS, Caceres A. 1996. MAP-1B/TAU functional redundancy during laminin-enhanced axonal growth. J Cell Sci 109(Pt 2):467-477.
22. Edelmann W, Zervas M, Costello P, Roback L, Fischer I, Hammarback JA, Cowan N, Davies P, Wainer B, Kucherlapati R. 1996. Neuronal abnormalities in microtubule-associated protein 1B mutant mice. Proc Natl Acad Sci USA 93:1270-1275.
23. Ferhat L, Kuriyama R, Lyons GE, Micales B, Baas PW. 1998. Expression of the mitotic motor protein CHO1/MKLP1 in postmitotic neurons. Eur J Neurosci 10:1383-1393.
24. Fischer I, Konola J, Cochary E. 1990. Microtubule associated protein (MAP1B) is present in cultured oligodendrocytes and co-localizes with tubulin. J Neurosci Res 27:112-124.
25. Fischer I, Romano-Clarke G. 1990. Changes in microtubule-associated protein MAP1B phosphorylation during rat brain development. J Neurochem 55:328-333.
26. Franzen R, Tanner SL, Dashiell SM, Rottkamp CA, Hammer JA, Quarles RH. 2001. Microtubule-associated protein 1B: a neuronal binding partner for myelin-associated glycoprotein. J Cell Biol 155:893-898.
27. Fukata Y, Itoh TJ, Kimura T, Menager C, Nishimura T, Shiromizu T, Watanabe H, Inagaki N, Iwamatsu A, Hotani H, et al. 2002. CRMP-2 binds to tubulin heterodimers to promote microtubule assembly. Nat Cell Biol 4:583-591.
28. Garcia-Perez J, Avila J, Diaz-Nido J. 1998. Implication of cyclin-dependent kinases and glycogen synthase kinase 3 in the phosphorylation of microtubule-associated protein 1B in developing neuronal cells. J Neurosci Res 52:445-452.
29. Garcia Rocha M, Avila J. 1995. Characterization of microtubule-associated protein phosphoisoforms present in isolated growth cones. Brain Res Dev Brain Res 89:47-55.
30. Gong CX, Wegiel J, Lidsky T, Zuck L, Avila J, Wisniewski HM, Grundke-Iqbal I, Iqbal K. 2000. Regulation of phosphorylation of neuronal microtubule-associated proteins MAP1b and MAP2 by protein phosphatase-2A and -2B in rat brain. Brain Res 853:299-309.
31. Gonzalez-Billault C, Avila J. 2000. Molecular genetic approaches to microtubule-associated protein function. Histol Histopathol 15:1177-1183.
32. Gonzalez-Billault C, Avila J, Caceres A. 2001. Evidence for the role of MAP1B in axon formation. Mol Biol Cell 12:2087-2098.
33. Gonzalez-Billault C, Demandt E, Wandosell F, Torres M, Bonaldo P, Stoykova A, Chowdhury K, Gruss P, Avila J, Sanchez MP. 2000. Perinatal lethality of microtubule-associated protein 1B-deficient mice expressing alternative isoforms of the protein at low levels. Mol Cell Neurosci 16:408-421.
34. Gonzalez-Billault C, Engelke M, Jimenez-Mateos EM, Wandosell F, Caceres A, Avila J. 2002a. Participation of structural microtubule-associated proteins (MAPs) in the development of neuronal polarity. J Neurosci Res 67:713-719.
35. Gonzalez-Billault C, Owen R, Gordon-Weeks PR, Avila J. 2002b. Microtubule-associated protein 1B is involved in the initial stages of axonogenesis in peripheral nervous system cultured neurons. Brain Res 943:56-67.
36. Goold RG, Owen R, Gordon-Weeks PR. 1999. Glycogen synthase kinase 3beta phosphorylation of microtubule-associated protein 1B regulates the stability of microtubules in growth cones. J Cell Sci 112(Pt 19):3373-3384.
37. Greene LA, Liem RK, Shelanski ML. 1983. Regulation of a high molecular weight microtubule-associated protein in PC12 cells by nerve growth factor. J Cell Biol 96:76-83.
38. Hammarback JA, Obar RA, Hughes SM, Vallee RB. 1991. MAP1B is encoded as a polyprotein that is processed to form a complex N-terminal microtubule-binding domain. Neuron 7:129-139.
39. Himmler A. 1989. Structure of the bovine tau gene: alternatively spliced transcripts generate a protein family. Mol Cell Biol 9:1389-1396.
40. Hummel T, Krukkert K, Roos J, Davis G, Klambt C. 2000. Drosophila Futsch/22C10 is a MAP1B-like protein required for dendritic and axonal development. Neuron 26:357-370.
41. Inagaki N, Chihara K, Arimura N, Menager C, Kawano Y, Matsuo N, Nishimura T, Amano M, Kaibuchi K. 2001. CRMP-2 induces axons in cultured hippocampal neurons. Nat Neurosci 4:781-782.
42. Kirschner M, Mitchison T. 1986a. Beyond self-assembly: from microtubules to morphogenesis. Cell 45:329-342.
43. Kirschner MW, Mitchison T. 1986b. Microtubule dynamics. Nature 324:621.
44. Kutschera W, Zauner W, Wiche G, Propst F. 1998. The mouse and rat MAP1B genes: genomic organization and alternative transcription. Genomics 49:430-436.
45. Kuznetsov SA, Rodionov VI, Nadezhdina ES, Murphy DB, Gelfand VI. 1986. Identification of a 34-kD polypeptide as a light chain of microtubule-associated protein-1 (MAP-1) and its association with a MAP-1 peptide that binds to microtubules. J Cell Biol 102:1060-1066.
46. Langkopf A, Guilleminot J, Nunez J. 1994. Two novel HMW MAP2 variants with four microtubule-binding repeats and different projection domains. FEBS Lett 354:259-262.
47. Lanier LM, Gertler FB. 2000. From Abl to actin: Abl tyrosine kinase and associated proteins in growth cone motility. Curr Opin Neurobiol 10:80-87.
48. Lucas FR, Goold RG, Gordon-Weeks PR, Salinas PC. 1998. Inhibition of GSK-3beta leading to the loss of phosphorylated MAP-1B is an early event in axonal remodeling induced by WNT-7a or lithium. J Cell Sci 111(Pt 10): 1351-1361.
49. Ma D, Chow S, Obrocka M, Connors T, Fischer I. 1999. Induction of microtubule-associated protein 1B expression in Schwann cells during nerve regeneration. Brain Res 823:141-153.
50. Mack TG, Koester MP, Pollerberg GE. 2000. The microtubule-associated protein MAP1B is involved in local stabilization of turning growth cones. Mol Cell Neurosci 15:51-65.
51. Mann SS, Hammarback JA. 1994. Molecular characterization of light chain 3. A microtubule binding subunit of MAP1A and MAP1B. J Biol Chem 269:11492-11497.
52. Mann SS, Hammarback JA. 1996. Gene localization and developmental expression of light chain 3: a common subunit of microtubule-associated protein 1A(MAP1A) and MAP1B. J Neurosci Res 43:535-544.
53. Mansfield SG, Diaz-Nido J, Gordon-Weeks PR, Avila J. 1991. The distribution and phosphorylation of the microtubule-associated protein MAP 1B in growth cones. J Neurocytol 20:1007-1022.
54. Matsuo N, Kawamoto S, Matsubara K, Okubo K. 1998. A novel SCG10-related gene uniquely expressed in the nervous system. Gene 215:477-481.
55. Meiri KF, Burdick D. 1991. Nerve growth factor stimulation of GAP-43 phosphorylation in intact isolated growth cones. J Neurosci 11:3155-3164.
56. Meixner A, Haverkamp S, Wassle H, Fuhrer S, Thalhammer J, Kropf N, Bittner RE, Lassmann H, Wiche G, Propst F. 2000. MAP1B is required for axon guidance and Is involved in the development of the central and peripheral nervous system. J Cell Biol 151:1169-1178.
57. Meixner A, Wiche G, Propst F. 1999. Analysis of the mouse MAP1B gene identifies a highly conserved 4.3 kb 3′ untranslated region and provides evidence against the proposed structure of DBI-1 cDNA. Biochim Biophys Acta 1445:345-350.
58. Montesinos ML, Foucher I, Conradt M, Mainguy G, Robel L, Prochiantz A, Volovitch M. 2001. The neuronal microtubule-associated protein 1B is under homeoprotein transcriptional control. J Neurosci 21:3350-3359.
59. Moreno FJ, Diaz-Nido J, Jimenez JS, Avila J. 1999. Distribution of CK2, its substrate MAP1B and phosphatases in neuronal cells. Mol Cell Biochem 191:201-205.
60. Noble M, Lewis SA, Cowan NJ. 1989. The microtubule binding domain of microtubule-associated protein MAP1B contains a repeated sequence motif unrelated to that of MAP2 and tau. J Cell Biol 109:3367-3376.
61. Noiges R, Eichinger R, Kutschera W, Fischer I, Nemeth Z, Wiche G, Propst F. 2002. Microtubule-associated protein 1A (MAP1A) and MAP1B: light chains determine distinct functional properties. J Neurosci 22:2106-2114.
62. Ohyu J, Takashima S. 1998. Decreased expression of microtubule-associated protein 5 (MAP5) in the molecular layer of cerebellum in preterm infants with olivocerebellar lesions. Brain Dev 20:22-26.
63. Paglini G, Pigino G, Kunda P, Morfini G, Maccioni R, Quiroga S, Ferreira A, Caceres A. 1998. Evidence for the participation of the neuron-specific CDK5 activator P35 during laminin-enhanced axonal growth. J Neurosci 18:9858-9869.
64. Papandrikopoulou A, Doll T, Tucker RP, Garner CC, Matus A. 1989. Embryonic MAP2 lacks the cross-linking sidearm sequences and dendritic targeting signal of adult MAP2. Nature 340:650-652.
65. Pedrotti B, Ulloa L, Avila J, Islam K. 1996. Characterization of microtubule-associated protein MAP1B: phosphorylation state, light chains, and binding to microtubules. Biochemistry 35:3016-3023.
66. Phillis R, Statton D, Caruccio P, Murphey RK. 1996. Mutations in the 8 kDa dynein light chain gene disrupt sensory axon projections in the Drosophila imaginal CNS. Development 122:2955-2963.
67. Pigino G, Paglini G, Ulloa L, Avila J, Caceres A. 1997. Analysis of the expression, distribution and function of cyclin dependent kinase 5 (cdk5) in developing cerebellar macroneurons. J Cell Sci 110(Pt 2):257-270.
68. Ramon-Cueto A, Avila J. 1997. Differential expression of microtubule-associated protein 1B phosphorylated isoforms in the adult rat nervous system. Neuroscience 77:485-501.
69. Ramon-Cueto A, Avila J. 1999. Two modes of microtubule-associated protein 1B phosphorylation are differentially regulated during peripheral nerve regeneration. Brain Res 815:213-226.
70. Ramon-Cueto A, Cordero MI, Santos-Benito FF, Avila J. 2000. Functional recovery of paraplegic rats and motor axon regeneration in their spinal cords by olfactory ensheathing glia. Neuron 25:425-435.
71. Ramon y Cajal S. 1904. Variaciones morfológicas normales y patológicas del retículo neurofibrilar. Trab Lab Invest Biol 3:1-26.
72. Riederer B, Cohen R, Matus A. 1986. MAP5: a novel brain microtubule-associated protein under strong developmental regulation. J Neurocytol 15:763-775.
73. Riederer BM. 1995. Differential phosphorylation of MAP1b during postnatal development of the cat brain. J Neurocytol 24:45-54.
74. Riederer BM, Moya F, Calvert R. 1993. Phosphorylated MAP1b, alias MAP5 and MAP1x, is involved in axonal growth and neuronal mitosis. NeuroReport 4:771-774.
75. Rochlin MW, Dailey ME, Bridgman PC. 1999. Polymerizing microtubules activate site-directed F-actin assembly in nerve growth cones. Mol Biol Cell 10:2309-2327.
76. Roos J, Hummel T, Ng N, Klambt C, Davis GW. 2000. Drosophila Futsch regulates synaptic microtubule organization and is necessary for synaptic growth. Neuron 26:371-382.
77. Sato-Yoshitake R, Shiomura Y, Miyasaka H, Hirokawa N. 1989. Microtubule-associated protein 1B: molecular structure, localization, and phosphorylation-dependent expression in developing neurons. Neuron 3:229-238.
78. Schoenfeld TA, McKerracher L, Obar R, Vallee RB. 1989. MAP 1A and MAP 1B are structurally related microtubule associated proteins with distinct developmental patterns in the CNS. J Neurosci 9:1712-1730.
79. Soares S, von Boxberg Y, Lombard MC, Ravaille-Veron M, Fischer I, Eyer J, Nothias F. 2002. Phosphorylated MAP1B is induced in central sprouting of primary afferents in response to peripheral injury but not in response to rhizotomy. Eur J Neurosci 16:593-606.
80. Takei Y, Kondo S, Harada A, Inomata S, Noda T, Hirokawa N. 1997. Delayed development of nervous system in mice homozygous for disrupted microtubule-associated protein 1B (MAP1B) gene. J Cell Biol 137:1615-1626.
81. Takei Y, Teng J, Harada A, Hirokawa N. 2000. Defects in axonal elongation and neuronal migration in mice with disrupted tau and map1b genes. J Cell Biol 150:989-1000.
82. Takemura R, Okabe S, Umeyama T, Kanai Y, Cowan NJ, Hirokawa N. 1992. Increased microtubule stability and alpha tubulin acetylation in cells transfected with microtubule-associated proteins MAP1B, MAP2 or tau. J Cell Sci 103(Pt 4):953-964.
83. Tanner SL, Franzen R, Jaffe H, Quarles RH. 2000. Evidence for expression of some microtubule-associated protein 1B in neurons as a plasma membrane glycoprotein. J Neurochem 75:553-562.
84. Teng J, Takei Y, Harada A, Nakata T, Chen J, Hirokawa N. 2001. Synergistic effects of MAP2 and MAP1B knockout in neuronal migration, dendritic outgrowth, and microtubule organization. J Cell Biol 155:65-76.
85. Tint I, Slaughter T, Fischer I, Black MM. 1998. Acute inactivation of tau has no effect on dynamics of microtubules in growing axons of cultured sympathetic neurons. J Neurosci 18:8660-8673.
86. Togel M, Wiche G, Propst F. 1998. Novel features of the light chain of microtubule-associated protein MAP1B: microtubule stabilization, self interaction, actin filament binding, and regulation by the heavy chain. J Cell Biol 143:695-707.
87. Tonge DA, Golding JP, Gordon-Weeks PR. 1996. Expression of a developmentally regulated, phosphorylated isoform of microtubule-associated protein 1B in sprouting and regenerating axons in vitro. Neuroscience 73:541-551.
88. Tucker RP, Binder LI, Matus AI. 1988. Neuronal microtubule-associated proteins in the embryonic avian spinal cord. J Comp Neurol 271:44-55.
89. Tucker RP, Garner C, Matus A. 1989. In situ localization of microtubule-associated protein mRNA in the developing and adult rat brain. Neuron 2:1245-1256.
90. Uchida Y. 2003. Overexpression of full length but not N-terminal truncated isoform of microtubule-associated protein 1B accelerates apoptosis of cultured cortical neurons. J Biol Chem 278:366-371.
91. Ulloa L, Avila J, Diaz-Nido J. 1993a. Heterogeneity in the phosphorylation of microtubule-associated protein MAP1B during rat brain development. J Neurochem 61:961-972.
92. Ulloa L, Diez-Guerra FJ, Avila J, Diaz-Nido J. 1994a. Localization of differentially phosphorylated isoforms of microtubule-associated protein 1B in cultured rat hippocampal neurons. Neuroscience 61:211-223.
93. Ulloa L, Dombradi V, Diaz-Nido J, Szucs K, Gergely P, Friedrich P, Avila J. 1993b. Dephosphorylation of distinct sites on microtubule-associated protein MAP1B by protein phosphatases 1, 2A and 2B. FEBS Lett 330:85-89.
94. Ulloa L, Montejo de Garcini E, Gomez-Ramos P, Moran MA, Avila J. 1994b. Microtubule-associated protein MAP1B showing a fetal phosphorylation pattern is present in sites of neurofibrillary degeneration in brains of Alzheimer's disease patients. Brain Res Mol Brain Res 26:113-122.
95. Vandecandelaere A, Pedrotti B, Utton MA, Calvert RA, Bayley PM. 1996. Differences in the regulation of microtubule dynamics by microtubule-associated proteins MAP1B and MAP2. Cell Motil Cytoskeleton 35:134-146.
96. Vecino E, Avila J. 2001. Distribution of the phosphorylated form of microtubule associated protein 1B in the fish visual system during optic nerve regeneration. Brain Res Bull 56:131-137.
97. Vecino E, Ulloa L, Avila J. 1996. Phosphorylated microtubule associated protein (MAP1B-Phos) in the retina during regeneration of the fish optic nerve. Int J Dev Biol Suppl 1:171S-172S.
98. Vecino E, Ulloa L, Avila J. 1998. The phosphorylated isoform of microtubule associated protein 1B (MAP1B) is expressed in the visual system of the tench (Tinca tinca, L) during optic nerve regeneration. Neurosci Lett 245:93-96.
99. Vouyiouklis DA, Brophy PJ. 1993. Microtubule-associated protein MAP1B expression precedes the morphological differentiation of oligodendrocytes. J Neurosci Res 35:257-267.
100. Waterman-Storer CM, Salmon E. 1999. Positive feedback interactions between microtubule and actin dynamics during cell motility. Curr Opin Cell Biol 11:61-67.
101. Waterman-Storer CM, Worthylake RA, Liu BP, Burridge K, Salmon ED. 1999. Microtubule growth activates Rac1 to promote lamellipodial protrusion in fibroblasts. Nat Cell Biol 1:45-50.
102. Wu HY, Dawson MR, Reynolds R, Hardy RJ. 2001. Expression of QKI proteins and MAP1B identifies actively myelinating oligodendrocytes in adult rat brain. Mol Cell Neurosci 17:292-302.
103. Yu W, Cook C, Sauter C, Kuriyama R, Kaplan PL, Baas PW. 2000. Depletion of a microtubule-associated motor protein induces the loss of dendritic identity. J Neurosci 20:5782-5791.
104. Zhang YQ, Bailey AM, Matthies HJ, Renden RB, Smith MA, Speese SD, Rubin GM, Broadie K. 2001. Drosophila fragile X-related gene regulates the MAP1B homolog Futsch to control synaptic structure and function. Cell 107:591-603.