Cytokinins prague
Transcript of Cytokinins prague
Characteristics of CRE1 cytokinin receptor
1000 aa long N terminal ligand binding domain ( 300 aa) Histidine kinase domain at the C terminus
followed by two receiver domains T 278 mutation causes the loss of function A part of the two component system
Thr 278
HK R RLB
TM
CYCLASES/HISTIDINE KINASES ASSOCIATED SENSORY
EXTRACELLULAR /CHASE/
200 – 230 aa Present in bacteria, lower eukaryotes and plants Bound at the C terminus Binds cytokinins and peptides Helices at the both ends Two internal helices divided by strands (a + b
fold) Mechanism of ligand binding and evolutional
relationships are unknown.
Evolutionary relationships to CHASE domain
(GRDB-Gene Related Data Base)
1jogA - sensory domain of the membraneous two-component fumarate - sensor Dcus from E. coli, 1p0zA - sensor kinase cita. 1e4eA, 1ehiA - D-Alanine-D-lactate ligase.
Structures of receptor domains selected by 3DHit as related to
1joga.
Domain 3d-hit score
PDB code
Function Organism Ligand
CACHE 84.3 1p0z Ca2+ channels and chemotaxis receptors
K.pneumoniae Citrate Anion
GAF 55.6 1mc0 cGMP phosphodiesterase, adenyl cyclase, FhlA domain
M.musculus Cyclic guanosine monophosphate
PAS/PYP 47.2 1f98 Periodic clock protein, aryl hydrocarbon receptor and single-minded protein/Photoactive Yellow Protein
E. halophila 4'-Hydroxycinnamic Acid
Profiln 46.2 1g5u monomeric actin binding H. brasiliensis Actin ACT - 1psdA1 Aspartate kinase –
chorismate mutase – TyrA E.coli Nicotinamide-
Adenine-Dinucleotide
Conclusions
CRE1 and 1mc0 are located on the same clade and may have common origin
Cre1 is lacking a strand they are structurally much more similar to each other then to other members of PAS/PYP superfamily
The ligands bound by both domains are also structurally similar
CACHE, PAS/PYP and Profilin form a separate branch. These two groups separated very early in evolution.
Most of the protein-ligand interaction fulfiled by closely related receptors which are diverse in primary structure but share a common structure.
S-RLK LRR-RLK C4-class(TNFR)
WAK(EGF)
PR5-RLK Lectin-class
S-domain LRR-domain Kinase-domain Lectin-domain
TM-domain
RCC1-like repeat
TNFR-like repeat
EGF-like repeat
PR5-like domain
Human skin fibroblasts can be grown in zeatin (40 to 200 µM) throughout their lifespan of about 300 days in the lab. It neither decreases nor increases the division potential of human cells.
Long term growth
Implications• Zeatin has no short-term or long term negative effects on human cells.
•Zeatin does not interfere with the genetic control of cellular lifespan, hence no danger of cancer induction.
Summary
1. Short-term or long-term treatment of human skin fibroblasts with zeatin (optimal dose 80 µM) has no toxic effects in terms of cell survival, growth, and lifespan.
2. Zeatin does not induce extra cell proliferation in human cells, and thus, it is not carcinogenic.
3. Zeatin treated cells maintain youthful characteristics in terms of morphology, cell size and actin cytoskeletal organization.
4. Zeatin treatment enhances the antioxidative enzyme activities of human cells against oxidative damage.
5. Zeatin treatment increases the stress tolerance ability of cells.
A time scale of radiolytic events in biological system
Interaction Time (sec) Events and Processes
Physical 10-18 - 10-15 Energy absorption, excitation and ionization
Physico-chemical 10-15 - 10-10 Rearrangement of ionized or excited molecules, formation of diffusible radicals such as •H, •OH, e-
aq
Chemical 10-10 - 10-3 Free radical reactions, molecular alterations, formation of bioradicals by indirect action. long lived lesions in macromolecules
Biochemical 10-3 - 104 Enzymatic reactions, recognition of lesions, repair, fixation of damage
Cellular level 104 - 107 Cell death, cell loss, division kinetics, mutation
Systemic(multicellular organisms)
108 - 1010 Hormonal effects, immune reactions, vascular changes, functional impairment, adaptation, carcinogenesis, ageing, death
Some of the events and processes are overlapping. The times indicated are approximate.
00 2 0
2 84 3
5 3
8 1 1 8 6
2 1 5
5 7 6 99 6
1 0 81 1 9
1 4 9
1 6 0
1 7 1 1 9 81 3 5
4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 1 6 0 1 8 0 2 0 0 2 2 0 2 4 0
5 0
1 0 0
2 0 00 . 0
0 . 1
0 . 2
0 . 3
0 . 4
0 . 5
w a v e l e n g t h [ n m ]
AB
SO
RB
AN
CE
2 2 0 2 4 0 2 6 0 2 8 0 3 0 0
N N
O
NH
N
C H 2
N H
A B
C
D
K i n e t i n
KINETIN(N6-Furfuryladenine)
� Naturally occurring plant growth factor (cytokinin)
Anti-Aging Mechanisms:� Retards senescence in plants� Anti-aging effects in human skin cells in culture
-slow & reverse alternations that naturally occur in cell-aging process� Powerful antioxidant (free radical scavenger-protection)
KINETIN(N6-Furfuryladenine)
� Plant growth factor (cytokinin)� Retards senescence in plants� Anti-aging effects in human skin cells in culture� Antioxidant (free radical scavenger)(Protection)
The Future of Cytokinins in Skin Care and Anti-Aging
New clinical applications of Kinetin ZEATIN – New product development In vitro screening for new cytokinins Mechanisms of action
MODIFIEDBASES
MALONDIALDEHYDE
(Tyr, Phe, Trp, Met, Cys, Ser, Lys)
NUCLEICACIDBASES
LIPIDS
PROTEINS
SUGARFURFURAL
PROPENAL
OH.
DNA
00 2 0
2 84 3
5 3
8 1 1 8 6
2 1 5
5 7 6 99 6
1 0 81 1 9
1 4 9
1 6 0
1 7 1 1 9 81 3 5
4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 1 6 0 1 8 0 2 0 0 2 2 0 2 4 0
5 0
1 0 0
2 0 00 . 0
0 . 1
0 . 2
0 . 3
0 . 4
0 . 5
w a v e l e n g t h [ n m ]
AB
SO
RB
AN
CE
2 2 0 2 4 0 2 6 0 2 8 0 3 0 0
N N
O
NH
N
C H 2
N H
A B
C
D
K i n e t i n
0.853
H2O1.527
0.716
O31.549
O2
H3O
0.993H2
1.516
1.520P1
0.903
H10A1.320
1.340
C21.357
N1
0.943
H10B
1.054
O4
1.358N3
1.469
1.483
C10
O1
H4O
1.411
1.337C6
0.953N61.374
1.369
C9
1.378C5
1.298 1.322C11
H6
H131.366
C13
1.330
0.808
N9H9
1.480
O15
1.332
0.935N7
0.934
C8
H7
1.252
1.058C12
H12
0.954
C14
H81
H14
a
bc
POCNH
A time scale of radiolytic events in biological system
Interaction Time (sec) Events and Processes
Physical 10-18 - 10-15 Energy absorption, excitation and ionization
Physico-chemical 10-15 - 10-10 Rearrangement of ionized or excited molecules, formation of diffusible radicals such as •H, •OH, e-aq
Chemical 10-10 - 10-3 Free radical reactions, molecular alterations, formation of bioradicals by indirect action. long lived lesions in macromolecules
Biochemical 10-3 - 104 Enzymatic reactions, recognition of lesions, repair, fixation of damage
Cellular level 104 - 107 Cell death, cell loss, division kinetics, mutation
Systemic(multicellular organisms)
108 - 1010 Hormonal effects, immune reactions, vascular changes, functional impairment, adaptation, carcinogenesis, ageing, death
Some of the events and processes are overlapping. The times indicated are approximate.
500 g DNA (herring sperm) → 275 mg KC.O. Miller et al. J. Amer. Chem. Soc. 78: 1375-1380 (1956)
22 mg DNA (salmon testes) → 12 µg I. Gawronska, 2005 – unpublished
Yield 0.2 %