Cyclic AMP regulation of glucose transport in germinating Pilobolus longipes spores
- 32 Downloads
- 4 Citations
Abstract
Pilobolus longipes spores were activated by either glucose or 6-deoxyglucose. Glucose-induced spore activation was previously shown to follow an increase in intracellular cyclic AMP. Concurrent with glucose-induced spore activation, were shifts in 6-deoxyglucose transport kinetics towards higher Vmax and Km values. Cyclic AMP derivatives also caused spore activation and similar changes in the kinetic parameters of 6-deoxyglucose transport. The time course of activation was paralleled by changes in transport activity. Inhibition of phosphodiesterase alone did not cause activation or induce changes in transport activity, but in combination with sub-optimal levels of either 6-deoxyglucose or cAMP derivatives, it amplified the germination signals to produce large increases in both spore activation and 6-deoxyglucose transport activity. These results support the conclusion that glucose transport in germinating spores is regulated by cAMP.
Key words
Pilobolus Cyclic AMP Spores Glucose 6-Deoxyglucose Transport Germination ActivationAbbreviations
- IBMX
3-isobutyl-1-methylxanthine; monobutyryl cyclic AMP
- N6
monobutyryladenosine 3′:5′-cyclic monophosphate
- 8-bromo cyclic AMP
8-bromoadenosine 3′:5′-cyclic monophosphate
References
- Bisson LF, Fraenkel DG (1983a) Involvement of kinases in glucose and fructose uptake by Saccharomyces cerevisiae. Proc Natl Acad Sci USA. 1730–1734Google Scholar
- Bisson LF, Fraenkel DG (1983b) Transport of 6-deoxyglucose in Saccharomyces cerevisiae. J Bacteriol 155:995–1000Google Scholar
- Bourret JA (1985) Glucose transport by germinating Pilobolus longipes spores. Exp Mycol 9:48–55Google Scholar
- Bourret JA (1986) Evidence that a glucose mediated rise in cyclic AMP triggers germination of Pilobolus longipes spores. Exp Mycol 10:60–66Google Scholar
- Bourret JA Keierleber C (1980) Iron and temperature as sporangiospore germination factors of Pilobolus longipes. Arch Microbiol 126:43–49Google Scholar
- Bourret JA, Kim H (1983) Glucose activation of Pilobolus longipes sporangiospores. Arch Microbiol 134:148–152Google Scholar
- Cushman SW, Wardzala LJ (1980) Potential mechanism of insulin action on glucose transport in the isolated rat adipose cell. J Biol Chem 255:4758–4762Google Scholar
- Franzusoff A, Cirillo VP (1982) Uptake and phosphorylation of 2-deoxy-D-glucose by wild-type and single-kinase strains of Saccharomyces cerevisiae. Biochim Biophys Acta 688:295–304Google Scholar
- Jaspers HTA, Van Steveninck J (1975) Transport-associated phosphorylation of 2-deoxy-D-glucose in Saccharomyces fragilis. Biochim Biophys Acta 406:370–385Google Scholar
- Suzuki K, Kono T (1980) Evidence that insulin causes translocation of glucose transport activity to the plasma membrane from an intracellular storage site. Proc Natl Acad Sci USA 77:2542–2545Google Scholar
- Tripp ML, Paznokas JL (1982) Glucose-initiated germination of Mucor racemosus sporangiospores J Gen Microbiol 128:477–483Google Scholar