4. Κανάλια ιόντων και μεταγωγή σήματος
DESCRIPTION
fTRANSCRIPT
-
1.
2.
3. - - - -
4. - (ligand-gated ion channel receptors)
Cys-loop
Gaba : NMDA
5. G-
6. (cGMP, cAMP) (3)
4o
-
80
1.
, . , , .. .
, .
. . - , .
-- . , , - . , , , GABA, , , , ( 4.1). . , - Ca2+ Ca2+ . Ca2+ .
4.1 . Kraus, Biochemistry of Signal Transduction, 2000.
-
81
( 4.2). - (ligand gated ion channels), G- -. , -.
- . -. : - Na+/K+ - Cl-. , .
4.2 . ,
. Ca2+ . , , . .
(), , G (), . G , cAMP. cAMP cAMP-, . Eric Kandel, , 2000.
-
82
2. : -
Na+ Cl-
, K+ , . , , . , , :
1. Na+ K+ . - Na+/K+.
2. K+ K+.
, . , 30mV 50 mV . , : Na+, , , , , K+ Cl- , . , , . : - Na+ , (msec) , ( +30mV). , K+, K+, , . msec, ( 4.3).
, - Ca2+ ( 4.4).
140 mM K+ 4 mM K+ 12 mM Na+ 150 mM Na+ 4 mM Cl- 120 mM Cl- 148 mM A- ( ) 34 mM A-
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83
4.3 . 1. . 2. a+
. 3. . 4. + . 5. .
4.4 . , .
1.
2.
3. 4.
5.
-
84
3. -
. :
- , .
-, , .
(effectors) . , Gai , G- (GPCRs).
, , . NMDA .
, , , .
-
- . , , a+, + Ca2+. : , 0,5 2 msec, a+, + Ca2+. msec. , 2 msec . . , , . , . : , . . . .
I: a+, + Ca2+ . , a+ 12 .
-
85
Ca2+ Ca2+ 1000 .
-
- 140 , (review Yo et al, 2005).
- a+ Eliktrophorus electricus, Ca2+ + shaker Drosophila. a+ Ca2+ , + .
- Na+ Ca2+ -, 1-4 . - 4 (-IV).
4.5 . - - Na+ ( Ca2+). - Na+ Ca2+ 4 (-IV). Yu et al, Overview of molecular relationships in the voltage-gated ion channel superfamily, Pharmacological Reviews, 2005, 57, 387-395. . - - (auxiliary subunit) Na+.
.
.
-
86
- + -, (-IV) - Na+ Ca2+.
4.6 - + . -
+ 4 -, I-IV Na+ Ca2+. - 6 (S1-S6),
-. S4 , SS1 SS2 . .
. 4.7 - -. 6 (S1-S6), -. S4 , SS1 SS2 .
, . , , , / . (gating current). , .
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87
S4 . S4 . 4. 8 S4. S4 + . S4. (R1, R2, R3, R4, K5, R6).
. . . S4 , , . S4 - - . .
4.9
( S4), , .
-
88
- (-IV). , , , , . a+ , , . SS1 SS2 ( 4.7). SS1 SS2, . , , SS1 SS2 . , S6 .
-
, . , msec sec, . a+, , , . a+: Na+
- ,
- . - 200 . , , .
, .
Ion passage and ion selectivity
4.10 Na+,
.
-
89
. .
-
- - , , (. ) , . , .
Na+ (1 4). , - , C- . , . Cys .
Ca2+ 4 (2, , , ). 2 , ( 2 ) . - . 4 , , .
+ -, - . .
4.11 - . Yu et al,
Overview of molecular relationships in the voltage-gated ion channel superfamily, Pharmacological Reviews, 2005, 57, 387-395.
-
90
4.12 - Ca2+. 1 2, , .
4. - (Ligand-gated ion channel receptors)
- - .
3 :
(2), , , - C- . 7 2, . 22/3, 21/5, 22/6, 24/6.
cys-loop , -, 5 (2) . 4 , C- - . , / / . , . 3 4 , . Cys-loop ( nAChR, 5-3, C-Zinc activated ion channel Zn2+) (- GABAA, GABAC ).
, 4 . - , , P loop, . C- . NMDA ( NR1 R2A, NR2B, NR2C, NR2D), AMPA .
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91
4.13 (A) :
(2), (GluR) Cys-loop (nAChR, 5HT3, ZAC, GABAA gly). (B) 4 /, . . Hogg RC., Buisson B., Bertrand D., Allosteric modulation of ligand-gated channels, Biochemical Pharmacology, 2005, 70, 1267-1276.
- , , : a+ Ca2+ , 5-3 , Cl- GABAA, GABAC . (depolarization) -. , 5-3 ( NMDA, AMPA ), . (hyperpolarization) -. GABAA GABAC , .
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92
, msec, (fast responding receptors), G, , G, .
- Cys-loop
O 5 (subunits) - : 4 , - , - .
4 EN (-V). 20-30
-, . ( 20) .
4.14 (A) GABAA. 5 (22)
. : 4 , NH2 COOH , 2 . Bormann J., The ABC of GABA receptors. TiPS, 2000, 21, 16-19. (B) 4 22 GABAA. 4 (1, 2, 3, 4). G.B. Smith and R.W.Olsen, TiPS 1995, 16, 162-167.
( ,
) ( 5,6 ). , . (Pro) .
Cys-
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93
, (Ser248, Ser254, Ser256, Ser262) , (non competitive blockers)* ( 4.15, 4.16). (. , , ) (), , N- -.
4.15 . -. 4 (1-4), 20-30 - . . . 2 . H.R. Arias, Brain Res.Rev., 1997, 25, 133-191.
() , 2 ( ) . CPZ (), (-), TID Arias H.R., Brain Res. Review, 1997, 25, 133-191.
* , . (D). . (J-P. Changeux et al, Achetylcholine receptor: an allosteric protein, Science, 1984, 225, 1335-1344).
A B
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94
4.16 .
-. (high affinity site) , 30 , (low affinity sites) . J-P. Changeux et al, Science, 1984, 225, 1335-1343. 1 E 2-
3 .
: , GABAA, Cl-, , , Na+ Ca2+. - , (driving force) .
2 . -
, cAMP. .
AMINOTEIKO AO (NH2-TERMINAL). , - , (Cys139 Cys153), S-S. Cys-Cys ,
, . . , , , ( - -). (2).
. (2) GABA (22) 5-3, -, . . , . 2001, Changeux, ( ACh). ( ) -, , ACh - - ( 4.17).
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95
ACh
ACh
ACh
4.17 () . ()
. () , . . . () , ACh, - -. () , Galzi and Changeux, 1995. -. () , Changeux 2001. -, - -. Lester et al, Cys-loop receptors: New twists and turns, Trends in Neurosciences, 2004, 27, 329-336. - - GABA
. GABA . GABA .
(COOH-TERMINAL).
G, , - .
-
96
. , . , . , . . 2-3 nm .
4.18 , . ) . , . . . ) 2 -, . Unwin, 1993.
.
-
-
97
.
prefilter
M2M2M2
4.19 () 2 .
( ) . .
() 2 . . 2 . (): 2 . . (): 2 . 2 . ( ) , . Unwin, 1995. , 2 . . , . , - , , 2. 2 . , . 2 , . .
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98
4.20 ACh, ACh. ACh Torpedo , Unwin et al (2003). (2). Ch () (). 2 - (), () . Colquhoun D., and Sivilotti L., Function and structure in glycine receptors and some of their relatives, Trends in Neurosciences, 2004, 27, 327-344.
4.21 ACh, ACh . Ch . Lester H., Dibas M., Dahan D., Leite JF., Dougherty DA., Cys-loop receptors: New twists and turns, Trends in Neurosiences, 2004, 27, 329-336.
GABA :
GABA . GABA ( , 17-20% GABA, ~6.000 ),
, -
, -
-
99
- GABAA, Cl- .
GABA :
GABA ,
GABA . GABA , 2, -
..
(.
). () GABA, , GABA. 6 - GABA ,
GABA.
E 4.22 GABA. GABA GABA
. GABAA - Cl-, () , (GABA spillover) GABAA , () .
Semyanov A, Walker M., Kullman D., Silver R., Tonically active GABAA receptors: modulating gain and maintaining the tone, Trends in Neurosciences 2004, 27, 262-269.
GABA :
(. CA1 ). () GABA, , GABA. 6 - GABA , GABA.
GABA , GABA . GABA ,
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100
2, - . , GABA GABA . GABA (ipsc) , GABA.
GABA
1. GABA: GABA -
: (1-6), (1-3), (1-3), , , . , . , GABA , .
GABA , . , .
(ipsps) GABA. ,
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101
. , CA1 GABA 1, 2 5 . , ipsps . ; , .
2. - GABA
, GABA . .
6 ( ) . 6 .
3. GABA,
. GABA , . , GABA , GA , .
4. GABA () () ,
GABA . , .
5. Cl- Cl- GABA
. , K+/ Cl- Cl-, Cl- GABA.
6. GABA
, . , GABA. /. Ser410 2 (Akt), GABA . , 2 / 3 .
7. GABA
. GABA , , , 5-, ACh .
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102
GABA GABA. GABA , GABA GABA . GPCR , GABA, Ca2+.
4.23 GABAA. , : (1) . (2) . (3) , C (PKC). (4) Cl-, K+/ Cl- (KCC2) . , : (5) Ca2+ (6) GABAB , (7) , , (8) , GB1 , (9) , , 5-, ACh. , , , (10). Mody I., Pearce R., Diversity of inhibitory neurotransmission trough GABAA receptors, Trends in Neurosciences, 2004, 27, 569-575.
-
- (Glu), . , , NMDA (--D-), AMPA (--3--5--4- ).
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103
, NMDA . NMDA LTP ( ). , Ca2+. NMDA . NMDA :
.
AMPA NMDA. NMDA Mg2+ ( Zn2+),
. , , Na+.
Mg2+ NMDA.
NMDA a+ Ca2+.
4.24 NMDA, ,
( ) . . NMDA ( Mg2+ ) ( Na+). . , NMDA, Mg2+ , a+ Ca2+. Ca2+ .
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104
NMDA
NMDA -, 4 : NR1 2 NR2A, NR2B, NR2C NR2D ( NR1-NR1-NR2A-NR2A).
3 (1, 3 4). 2 2 . 2 , , S1, S2 ( 4 , , ). COO- , .
4.25 NMDA. (NR1-NR4). 3 (1, 3 4). 2 2 .
4.26 . D (Amino Terminal Domain) 2 , . S1 , 1 , 2 3 . 3 4 S2 . S1 S2 . CTD (Carboxy Terminal Domain) . Wollmuth L., Sobolevsky A., Structure and gating of the glutamate receptor ion channel, Trends in eurosciences, 2004, 27, 321-328.
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105
2 . 2 -, , 1 3 . Q/R/N . (Q), (R) , () DA ( 4.28).
4.27 2 .
+ + . + 6 ( 4.6). , + . 2 +. . .
4.28 +. + . 2 ( ) & Q/R/N . Wollmuth L., Sobolevsky A., Structure and gating of the glutamate receptor ion channel, Trends in eurosciences, 2004, 27, 321-328.
2
3
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106
NMDA 2 NMDA . QRN . 4.29 -615 () R2 616 (+1) R1. . NMDA Ca2+ Mg2+. , NMDA Mg2+.
4.29 NMDA Mg2+. (616)
2 R1 (615) NR2B . Ca2+ Mg2+.
NMDA
Q/R/N , 3 -. SYTAANLAAF, . NMDA SYTAANLAAF. 4.30, SYTAANLAAF 3 . , - 3 . AMPA . NMDA Ca2+ AMPA. - 3. S1 S2 S2 8 Amstrong ( ). 3, 3 . 3
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107
2 , ( 4.31).
4.30 () 2 3 - . (Q582) Q/R/N 2 - SYTAANLAAF ( ) 3 -. 3 , . () SYTAANLAAF 3 , DA ( ) ( ). Wollmuth L., Sobolevsky A., Structure and gating of the glutamate receptor ion channel, Trends in eurosciences, 2004, 27, 321-328.
4.31 .
.
.
3
R1 R2
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108
NMDA, -, . NMDA , PCP, .
4.32 NMDA.
5. G-
G-. , , G-. GPCR G-. . + Gi Gq. GIRK ( Kir) (G protein-coupled inwardly rectifying potassium channels: G- +) , , . GPCRs ( 2, 2, D2, 5-1, GABA), G . GIRK, +, + ( ). , GIRK ACh, 2 .
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109
GPCR, - G, GDP GTP. G-GTP G-, G . G GIRK G . Gi, G GIRK . + ( +, + ). G GTP GDP, G . Gq, GIRK , . Gq PLC, (2), (3) (DAG). PKC, , .
4.33 GIRK, G . . Gi , G , . . Gq , PKC 2 . Breitwieser GE, GIRK channels: hierarchy of control. Focus on "PKC-delta sensitizes Kir3.1/3.2 channels to changes in membrane phospholipid levels after M3 receptor activation in HEK-293 cells". Am J Physiol Cell Physiol. 2005, 289, C509-11.
+,
. + , . , +, , ( ) Mg2+, .
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110
GIRK . 4 . (1 2) . .
4.34 G (GIRK).
(1 2) , . .
6.
(CAMP, cGMP) (3).
, cGMP cAMP, (cGMP- ) (cAMP- ) . : (). , G- (), - (effector). cGMP. cGMP. cGMP Ca2+ Na+ . cGMP . cGMP , Ca2+ Na+ .
GIRKGIRKVoltagegatedK+Channel
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111
4.35 . (R) . cis/trans . (R*) G- . Gt,a cGMP (PDE), cGMP GMP. PDE , , . PDE cGMP. cGMP Na+ Ca2+ . cGMP , Na+ Ca2+ . . , cGMP cGMP . cGMP , Na+ Ca2+ .
: GPCR. , G- , cAMP. cAMP Ca2+ Na+ . cAMP , Ca2+ Na+ , .
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112
4.36 . (R) . , G- (AC), cAMP. cAMP Ca2+ Na+. cAMP , Ca2+ Na+ , . Trudeau M., Zagotta W., Calcium/calmodulin modulation of olfactory and rod cyclic nucleotide-gated ion channels, J. Biol. Chem., 2003, 278, 21, 18705-18708.
cGMP cAMP . 4 . 6 , - - . +,
. cAMP/cGMP C- - (, , C) 8 (1-8).
4.37 ( 4) . cAMP/cGMP - (, , C) 8 (1-8). Biel M et al, Arch. Pharmacol., 1998, 358.
(CNG: cyclic
nucleotide gated ion channels) Ca2+. Ca2+ , Ca2+/, -
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113
(cAMP, cGMP). feed-back -. 4.38 (CNG) (). cAMP/cGMP , Ca2+/ - . Ca2+/ - C- , cAMP/cGMP. Trudeau M., Zagotta W., Calcium/calmodulin modulation of olfactory and rod cyclic nucleotide-gated ion channels, J. Biol. Chem., 2003, 278, 21, 18705-18708.
(3)
InsP3, Ca2+ (InsP3). 3 Ca2+ . 15.000 , , Ca2+ .
- 3
1,4,5 (IP3) Ca2+ Ca2+ IP3. , , . IP3Rs : Ca2+ , Golgi .
-
114
4.39 () P3. 6 2 , NH2- IP3. 5 6 . () 4 IP3R. (,) . Bosanac et al, Structural insights into the regulatory mechanisms of IP3 receptors, Biochimica et Biophysica Acta 2004, 1742, 89-102. IP3Rs . ( 2700 ) (R) , - C- . 5 6, IP3Rs.
IP3R, - 226-576, IP3. IP3Rs 4 . 3 3 - .
3 1 TMR (~1600 ) , IP3Rs. , , IP3Rs : 3, .
IP3Rs 3 Ca2+. 3 - IP3R Ca2+ ( IP3) Ca2+. 3 Ca2+
()
() () ()
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115
- C- , .
4.40 - P3. : , Ca2+, 3 ( ). Taylor C., da Fonseca C., Morris E., IP3 receptors: he search for structure, Trends in Biological Sciences, 2004, 29, 210-219.
4.41 - 3. ()
, (suppressor) - 1 (gatekeeper) C- 2 , . () 3 - , Ca2+. 3 Ca2+ - C- , . () Ca2+- - (gatekeeper) C- . Taylor C., et al, TiPs, 2004, 29, 210-219.
-
() () ()
-
116
Ca2+ . 3 20 Ca2+. (CAM: calmodulin), -, Ca2+/- (CAM-kinases).
: , G ( G ) cAMP, cGMP, 3.
1. GPCR, G
2. C
IP3 DAG 3. (DAG)
4. IP3 - Ca2+
5. To Ca2+
6. Ca2+ , -.
-
117
-
GPCR - G -
GPCR G Effector -
4.42 , . ) -: . ) G: . ) (cAMP, cGMP), .
Arias H.R., Topology of ligand binding sites on the nicotinic acetylcholine receptor, Brain Res. Rev., 1997, 25, 133-191.
Arias H.R., Localization of agonist and competitive antagonist binding sites on nicotinic acetylcholine receptors, Neurochem Int. 2000, 36, 595-645.
Barnard E.A., The transmitter-gated channels: a range of receptor types and structures, TiPS, 1996, 17, 305-308
Biel M., Sautter A., Ludwig A, Hoffmann F., Zong X., Cyclic nucleotide-gated channels mediators of NO: cGMP-regulated processes, Naunyn-Schiedebergs Arch. Pharmacol., 1998, 358, 140-144.
Bradley J., Reisert J., Frings S., Regulation of cyclic nucleotide-gated channels, Current Opinion in Neurobiology, 2005, 15, 343-349.
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Cascio M., Structure and Function of the glycine receptorand related nicotinicoid receptors, J. Biol. Chem., 2004, 279, 19383-19386.
()
()
()
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118
Catterall WA., Structure and function of voltage-gated ion channels, Ann. Rev. Biochem., 1995, 64, 493-531.
Changeux J-P., Le recepteur de lacetylcholine, un canal ionique membranaire regle de maniere allosterique par un neurotransmetteur, Ann. Institut Pasteur, 1992, 231-239
Colquhoun D., and Sivilotti L., Function and structure in glycine receptors and some of their relatives, Trends in Neurosciences, 2004, 27, 327-344
Connolly CN., and Wafford KA., The Cys-loop superfamily of ligand-gated ion channels: the impact of receptor structure and function, Biochemical Society Transactions, 2004, 32, 529-533.
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Mody I., Pearce R., Diversity of inhibitory neurotransmission trough GABAA receptors, Trends in Neurosciences, 2004, 27, 569-575.
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Semyanov A, Walker M., Kullman D., Silver R., Tonically active GABAA receptors: modulating gain and maintaining the tone, Trends in Neurosciences 2004, 27, 262-269.
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119
Schofield P.R. et al, Sequence and functional expression of the GABAA receptor shows a ligand-gated receptor superfamily, Nature, 1987, 328, 221-227.
Trudeau M., Zagotta W., Calcium/calmodulin modulation of olfactory and rod cyclic nucleotide-gated ion channels, J. Biol. Chem., 2003, 278, 21, 18705-18708.
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u F., Yarov-Yarovoy V., Gutman G., Catterall W., Overview of molecular relationships in the voltage-gated ion channel superfamily, Pharmacological reviews, 2005, 57, 387-395
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