Biomaterial Database

Long-term expression of c-H-ras stimulates Na-H and Na(+)-dependent Cl-HCO3 exchange in NIH-3T3 fibroblasts. 1994

D L Kaplan, and W F Boron

Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510.

In a study of intracellular pH (pHi) regulation, we compared c-H-ras-transformed fibroblasts (FT9s) with parental NIH 3T3 cells. Cells were grown on a coverslip and placed in a flow-through cuvette; pHi was monitored using a fluorescent dye. Whether cells were in a CO2-free or CO2-containing solution, steady-state pHi was approximately 0.5 higher in FT9s than in 3T3s. Rates of pHi recovery from acid loads in the presence of CO2 indicate that total net acid extrusion (Jtotal) was far greater in FT9s than 3T3s in the pHi range 6.3-7.4. In both FT9s and 3T3s, pHi recovery was blocked by removing Na+. In FT9s, most of Jtotal was blocked by ethyl isopropyl amiloride (EIPA) and was probably due to Na-H exchange. A smaller component was inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS) and required Cl- and was probably due to Na(+)-dependent Cl-HCO3 exchange. In 3T3s, the DIDS-sensitive and Cl(-)-dependent components of Jtotal were very small. The dominant acid-extruder in 3T3s appears to be a Na-H exchanger insensitive to 50 microM EIPA. We determined the flux-pHi relationships for both the Na-H and Na(+)-dependent Cl-HCO3 exchangers in both FT9s and 3T3s. p21ras alkaline shifts the pHi profile of each transporter by approximately 0.7, without affecting the Vmax. These shifts in the flux-pHi relationships provide a mechanism for the large increase in steady-state pHi produced by long-term expression of p21ras.

UI	MeSH Term	Description	Entries
D011905	Genes, ras	Family of retrovirus-associated DNA sequences (ras) originally isolated from Harvey (H-ras, Ha-ras, rasH) and Kirsten (K-ras, Ki-ras, rasK) murine sarcoma viruses. Ras genes are widely conserved among animal species and sequences corresponding to both H-ras and K-ras genes have been detected in human, avian, murine, and non-vertebrate genomes. The closely related N-ras gene has been detected in human neuroblastoma and sarcoma cell lines. All genes of the family have a similar exon-intron structure and each encodes a p21 protein.	Ha-ras Genes,Ki-ras Genes,N-ras Genes,c-Ha-ras Genes,c-Ki-ras Genes,c-N-ras Genes,ras Genes,v-Ha-ras Genes,v-Ki-ras Genes,H-ras Genes,H-ras Oncogenes,Ha-ras Oncogenes,K-ras Genes,K-ras Oncogenes,Ki-ras Oncogenes,N-ras Oncogenes,c-H-ras Genes,c-H-ras Proto-Oncogenes,c-Ha-ras Proto-Oncogenes,c-K-ras Genes,c-K-ras Proto-Oncogenes,c-Ki-ras Proto-Oncogenes,c-N-ras Proto-Oncogenes,ras Oncogene,v-H-ras Genes,v-H-ras Oncogenes,v-Ha-ras Oncogenes,v-K-ras Genes,v-K-ras Oncogenes,v-Ki-ras Oncogenes,Gene, Ha-ras,Gene, Ki-ras,Gene, v-Ha-ras,Gene, v-Ki-ras,Genes, Ha-ras,Genes, Ki-ras,Genes, N-ras,Genes, v-Ha-ras,Genes, v-Ki-ras,H ras Genes,H ras Oncogenes,H-ras Gene,H-ras Oncogene,Ha ras Genes,Ha ras Oncogenes,Ha-ras Gene,Ha-ras Oncogene,K ras Genes,K ras Oncogenes,K-ras Gene,K-ras Oncogene,Ki ras Genes,Ki ras Oncogenes,Ki-ras Gene,Ki-ras Oncogene,N ras Genes,N ras Oncogenes,N-ras Gene,N-ras Oncogene,c H ras Genes,c H ras Proto Oncogenes,c Ha ras Genes,c Ha ras Proto Oncogenes,c K ras Genes,c K ras Proto Oncogenes,c Ki ras Genes,c Ki ras Proto Oncogenes,c N ras Genes,c N ras Proto Oncogenes,c-H-ras Gene,c-H-ras Proto-Oncogene,c-Ha-ras Gene,c-Ha-ras Proto-Oncogene,c-K-ras Gene,c-K-ras Proto-Oncogene,c-Ki-ras Gene,c-Ki-ras Proto-Oncogene,c-N-ras Gene,c-N-ras Proto-Oncogene,ras Gene,ras Oncogenes,v H ras Genes,v H ras Oncogenes,v Ha ras Genes,v Ha ras Oncogenes,v K ras Genes,v K ras Oncogenes,v Ki ras Genes,v Ki ras Oncogenes,v-H-ras Gene,v-H-ras Oncogene,v-Ha-ras Gene,v-Ha-ras Oncogene,v-K-ras Gene,v-K-ras Oncogene,v-Ki-ras Gene,v-Ki-ras Oncogene
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D006133	Growth Substances	Signal molecules that are involved in the control of cell growth and differentiation.	Mitogens, Endogenous,Endogenous Mitogens
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000584	Amiloride	A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)	Amidal,Amiduret Trom,Amiloberag,Amiloride Hydrochloride,Amiloride Hydrochloride, Anhydrous,Kaluril,Midamor,Midoride,Modamide,Anhydrous Amiloride Hydrochloride,Hydrochloride, Amiloride,Hydrochloride, Anhydrous Amiloride,Trom, Amiduret
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001639	Bicarbonates	Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity.	Bicarbonate,Bicarbonate Ions,Hydrogen Carbonates,Bicarbonate Ion,Carbonic Acid Ions,Hydrogen Carbonate,Carbonate, Hydrogen,Carbonates, Hydrogen,Ion, Bicarbonate,Ions, Bicarbonate,Ions, Carbonic Acid
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D016283	Proto-Oncogene Proteins p21(ras)	Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and are involved in signal transduction as monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 3.6.1.47.	Proto-Oncogene Proteins c-ras,c-Ha-ras p21,c-Ki-ras p21,p21(N-ras),p21(c-Ha-ras),p21(c-Ki-ras),p21(c-ras),p21(ras),ras Proto-Oncogene Protein p21,Proto-Oncogene Protein p21(c-Ha-ras),Proto-Oncogene Protein p21(c-Ki-ras),Proto-Oncogene Protein p21(c-N-ras),Proto-Oncogene Protein p21(ras),Proto-Oncogene Protein ras,c-ras Proteins,p21 c-H-ras,p21 c-Ha-ras,p21 c-K-ras,p21 c-Ki-ras,p21 c-ras,ras Proto-Oncogene Product p21,Proteins c-ras, Proto-Oncogene,Proto Oncogene Protein ras,Proto Oncogene Proteins c ras,c Ha ras p21,c Ki ras p21,c ras Proteins,c-H-ras, p21,c-Ha-ras, p21,c-K-ras, p21,c-Ki-ras, p21,c-ras, Proto-Oncogene Proteins,c-ras, p21,p21 c H ras,p21 c Ha ras,p21 c K ras,p21 c Ki ras,p21 c ras,p21, c-Ha-ras,p21, c-Ki-ras,ras Proto Oncogene Product p21,ras Proto Oncogene Protein p21,ras, Proto-Oncogene Protein