Differentiation of African trypanosomes is controlled by a density sensing mechanism which signals cell cycle arrest via the cAMP pathway
Tóm tắt
Differentiation of African trypanosomes from replicating slender bloodstream forms to nondividing stumpy forms limits the parasite population size, allowing survival of the mammalian host and establishment of a stable host-parasite relationship. Using a novel in vitro culture system we have shown that slender to stumpy differentiation is induced by parasite density alone and thus is independent of host cues. Here we investigate the density sensing mechanism and show that trypanosomes release a soluble activity of low relative molecular mass, termed stumpy induction factor (SIF), which accumulates in conditioned medium. SIF activity triggers cell cycle arrest in G1/G0 phase and induces differentiation with high efficiency and rapid kinetics. Membrane-permeable derivates of cAMP or the phosphodiesterase inhibitor etazolate perfectly mimic SIF activity. Furthermore, SIF activity elicits an immediate two-to threefold elevation of intracellular cAMP content upon addition to slender forms. We conclude that SIF and hence density sensing operate through the cAMP signalling pathway. Temporal correlation of markers indicates that cell cycle arrest invariably precedes differentiation. Thus, our results indicate that the cell cycle regulation of blood-stream forms is under dominant control of cAMP signalling. Irreversible commitment to the quiescent state is elicited by a cAMP agonist within a period shorter than one complete cell cycle.
Từ khóa
Tài liệu tham khảo
Alexandre, 1990, Differential expression of a family of putative adenylate/guanylate cyclase genes in Trypanosoma brucei, Mol. Biochem. Parasitol, 43, 279, 10.1016/0166-6851(90)90152-C
Balber, 1972, Trypanosoma brucei: fluxes of the morphological variants in intact and X-irradiated mice, Exp. Parasitol, 31, 307, 10.1016/0014-4894(72)90122-1
Barry, 1991, The dynamics of antigenic variation and growth of African trypanosomes, Parasitol. Today, 7, 207, 10.1016/0169-4758(91)90143-C
Bergmeyer, 1974, Methoden der Enzymatischen Analyse, 3rd edn. Verlag Chemie, Weinheim
Black, 1985, Regulation of parasitaemia in mice infected with Trypanosoma brucei, Current Topic Microbiol. Immunol, 117, 93
Boshart, 1997, Protein phosphorylation and protein kinases in trypanosomatids, Trypanosomiasis and Leishmaniasis, 227
Boynton, 1983, The role of cyclic AMP in cell proliferation: a critical assessment of the evidence, Adv. Cyclic Nucleotide Res, 15, 193
Burgering, 1995, Regulation of ras-mediated signaling -more than one-way to skin a cat, Trends Biochem. Sci, 20, 18, 10.1016/S0968-0004(00)88944-6
Carruthers, 1992, High-efficiency clonal growth of bloodstream- and insect-form Trypanosoma brucei on agarose plates, Proc. Nat. Acad. Sci. USA, 89, 8818, 10.1073/pnas.89.18.8818
Chasin, 1972, 1-ethyl-4-(isopropylidenehydrazino)-1H-pyrozolo-(3,4-b)-pyridine-5-carboxylic acid, ethyl ester, hydrochloride (SQ 20009)-a potent new inhibitor of cyclic 3′,5′-nucleotide phosphodiesterases, Biochem. Pharmacol, 21, 2443, 10.1016/0006-2952(72)90414-5
Clarke, 1995, PSF and CMF, autocrine factors that regulate gene expression during growth and early development of Dictyostelium, Experientia, 51, 1124, 10.1007/BF01944730
Clayton, 1996, Metabolic compartimentation in African trypanosomes, Parasitol. Today, 12, 465, 10.1016/S0169-4758(96)10073-9
Cross, 1996, Antigenic variation in trypanosomes: secrets surface slowly, BioEssays, 18, 283, 10.1002/bies.950180406
de Gee, 1988, Genetics of resistance to the African trypanosomes. VI. Heredity of resistance and variable surface glycoprotein-specific immune responses, J. Immunol, 140, 283, 10.4049/jimmunol.140.1.283
Dumont, 1989, The cyclic AMP-mediated stimulation of cell proliferation, Trends Biochem. Sci, 14, 67, 10.1016/0968-0004(89)90046-7
Fraidenraich, 1993, Stimulation of Trypanosoma cruzi adenylyl-cyclase by an α(d)-globin fragment from Triatoma hindgut -effect on differentiation of epimastigote to trypomastigote forms, Proc. Nat. Acad. Sci. USA, 90, 10140, 10.1073/pnas.90.21.10140
Fuqua, 1994, Quorum sensing in bacteria: the LuxR-LuxI family of cell density-responsive transcriptional regulators, J. Bacteriol, 176, 269, 10.1128/jb.176.2.269-275.1994
Garbers, 1989, Guanylate cyclase, a cell surface receptor, J. Biol. Chem, 264, 9103, 10.1016/S0021-9258(18)60495-8
Geiger, 1992, Role of cGMP and cGMP-dependent protein kinase in nitrovasodilator inhibition of agonist-evoked calcium elevation in human platelets, Proc. Nat. Acad. Sci. USA, 89, 1031, 10.1073/pnas.89.3.1031
Giffin, 1986, Polyamine depletion following exposure to DL-α-difluoromethylornithine both in vivo and in vitro initiates morphological alterations and mitochondrial activation in a monomorphic strain of Trypanosoma brucei brucei, J. Protozool, 33, 238, 10.1111/j.1550-7408.1986.tb05599.x
Gonzales-Perdomo, 1988, Cyclic AMP and adenylate cyclase activators stimulate Trypanosoma cruzi differentiation, Exp. Parasitol, 66, 205, 10.1016/0014-4894(88)90092-6
Grossman, 1995, Genetic networks controlling the initiation of sporulation and the development of genetic competence in Bacillus subtilis, Ann. Rev. Gen, 29, 477, 10.1146/annurev.ge.29.120195.002401
Hamm, 1990, Differentiation of Trypanosoma brucei bloodstream trypomastigotes from long slender to short stumpy-like forms in axenic culture, Mol. Biochem. Parasitol, 40, 13, 10.1016/0166-6851(90)90075-W
Hesse, 1995, A novel cultivation technique for long-term maintenance of bloodstream form trypanosomes in vitro, Mol. Biochem. Parasitol, 70, 157, 10.1016/0166-6851(95)00027-X
Hirumi, 1989, Continuous cultivation of Trypanosoma brucei bloodstream forms in a medium containing a low concentration of serum protein without feeder cell layers, J. Parasitol, 75, 985, 10.2307/3282883
Jain, 1992, A density-sensing factor controls development in Dictyostelium, Genes Dev, 6, 390, 10.1101/gad.6.3.390
Kato, 1994, Cyclic AMP-induced G1 phase arrest mediated by an inhibitor (p27Kip1) of cyclin-dependent kinase 4 activation, Cell, 79, 487, 10.1016/0092-8674(94)90257-7
Kim, 1992, Control of cell density and pattern by intercellular signalling in Myxococcus development, Annu. Rev. Microbiol, 46, 117, 10.1146/annurev.mi.46.100192.001001
L’Allemain, 1997, Cyclin D1 expression is a major target of the cAMP-induced inhibition of cell cycle entry in fibroblasts, Oncogene, 14, 1981, 10.1038/sj.onc.1201038
Lanham, 1970, Isolation of salivarian trypanosomes from man and other mammals using DEAE-cellulose, Exp. Parasitol, 28, 521, 10.1016/0014-4894(70)90120-7
Mancini, 1981, Cyclic 3′, 5′-adenosine monophosphate levels during the developmental cycle of Trypanosoma brucei brucei in the rat, Mol. Biochem. Parasitol, 3, 19, 10.1016/0166-6851(81)90074-8
Matthews, 1994, Evidence for an interplay between cell cycle progression and the initiation of differentiation between life cycle forms of African trypanosomes, J. Cell Biol, 125, 1147, 10.1083/jcb.125.5.1147
Matthews, 1994, Cycles within cycles -the interplay between differentiation and cell-division in Trypanosoma brucei, Parasitol. Today, 10, 473, 10.1016/0169-4758(94)90159-7
McKenzie, 1996, cAMP-mediated growth inhibition in fibroblasts is not mediated via mitogen-activated protein (MAPp) kinase (ERK) inhibition, J. Biol. Chem, 271, 13476, 10.1074/jbc.271.23.13476
McLintock, 1990, A comparison of multiplication rates in primary and challenge infections of Trypanosoma brucei bloodstream forms, Parasitol, 101, 49, 10.1017/S0031182000079749
Mottram, 1994, Cdc2-related protein-kinases and cell-cycle control in trypanosomatids, Parasitol. Today, 10, 253, 10.1016/0169-4758(94)90136-8
Overath, 1983, Repression of glycoprotein synthesis and release of surface coat during transformation of Trypanosoma brucei. EMBO J, 1721
Paindavoine, 1992, A gene from the variant surface glycoprotein expression site encodes one of several transmembrane adenylate cyclases located on the flagellum of Trypanosoma brucei, Mol. Cell. Biol, 12, 1218
Pays, 1997, Cell signalling in trypanosomatids, Trypanosomiasis and Leishmaniasis, 199
Penketh, 1991, The effects of the methylating agent 1,2-Bis(methylsulfonyl)-1-methylhydrazine on morphology, DNA content and mitochondrial function of Trypanosoma brucei subspecies, J. Protozool, 38, 172, 10.1111/j.1550-7408.1991.tb04425.x
Priest, 1994, Developmental regulation of mitochondrial biogenesis in Trypanosoma brucei, J. Bioenerg. Biomembr, 26, 179, 10.1007/BF00763067
Rangel-Aldao, 1988, Cyclic AMP as an inducer of the cell differentiation of Trypanosoma cruzi, Biochem. Internat, 17, 337
Reed, 1985, Effect of theophylline on differentiation of Trypanosoma brucei, Infect. Immun, 49, 844, 10.1128/iai.49.3.844-847.1985
Roditi, 1989, Procyclin gene expression and loss of the variant surface glycoprotein during differentiation of Trypanosoma brucei, J. Cell Biol, 108, 737, 10.1083/jcb.108.2.737
Rolin, 1993, Transient adenylate cyclase activation accompanies differentiation of Trypanosoma brucei from bloodstream to procyclic forms, Mol. Biochem. Parasitol, 61, 115, 10.1016/0166-6851(93)90164-S
Sandberg, 1991, Characterization of Sp-5,6-dichloro-1-b-D-ribofuranosyl-benzimidazole-3′,5′-monophosphorothioate (Sp-5,6-DCl-cBiMPS) as a potent and specific activator of cyclic-AMP-dependent protein kinase in cell extracts and intact cells, Biochem. J, 279, 521, 10.1042/bj2790521
Seed, 1988, Growth of pleomorphic Trypanosoma brucei rhodesiense in irradiated inbred mice, J. Parasitol, 74, 781, 10.2307/3282254
Seed, 1989, African trypanosomes: inheritance of factors involved in resitance, Exp. Parasitol, 69, 1, 10.1016/0014-4894(89)90164-1
Seed, 1989, Mechanism of long slender (LS) to short stumpy (SS) transformation in the African trypanosomes, J. Protozool, 36, 572, 10.1111/j.1550-7408.1989.tb01099.x
Selzer, 1996, Down-regulation of S-adenosyl-L-methionine decarboxylase activity of Trypanosoma brucei during transition from long slender to short stumpy-like forms in axenic culture, Eur. J. Cell Biol, 69, 173
Turner, 1995, Replication, differentiation, growth and the virulence of Trypanosoma brucei infections, Parasitol, 111, 289, 10.1017/S0031182000081841
Vassella, 1996, High molecular mass agarose matrix supports growth of bloodstream forms of pleomorphic Trypanosoma brucei strains in axenic culture, Mol. Biochem. Parasitol, 82, 91, 10.1016/0166-6851(96)02727-2
Vickerman, 1965, Polymorphism and mitochondrial activity in sleeping sickness trypanosomes, Nature, 208, 762, 10.1038/208762a0
Vickerman, 1985, Developmental cycles and biology of pathogenetic trypanosomes, Br. Med. Bull, 41, 105, 10.1093/oxfordjournals.bmb.a072036
Woodward, 1990, Timing of nuclear and kinetoplast DNA replication and early morphological events in the cell cycle of Trypanosoma brucei. J. Cell Sci, 49