𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Cell density and amino acid transport in 3T3, SV3T3, and SV3T3 revertant cells

✍ Scribed by Angelo F. Borghetti; Giuseppe Piedimonte; Mariarosaria Tramacere; Alberto Severini; Paolo Ghiringhelli; Guido G. Guidotti

Publisher
John Wiley and Sons
Year
1980
Tongue
English
Weight
901 KB
Volume
105
Category
Article
ISSN
0021-9541

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The transport of selected neutral and cationic amino acids has been studied in Balb/c 3T3, SV3T3, and SV3T3 revertant cell lines. After properly timed preincubations to control the size of internal amino acid pools, the activity of systems A, ASC, L, and Ly^+^ has been discriminated by measurements of amino acid uptake (initial entry rate) in the presence and absence of sodium and of transportspecific model substrates. L‐Proline, 2‐aminoisobutyric acid, and glycine were primarily taken up by system A; L‐alanine and L‐serine by system ASC; L‐phenylalanine by system L; and L‐lysine by system Ly^+^ in SV3T3 cells. L‐Proline and L‐serine were also preferential substrates of systems A and ASC, respectively, in 3T3 and SV3T3 revertant cells. Transport activity of the Na^+^‐dependent systems A and ASC decreased markedly with the increase of cell density, whereas the activity of the Na^+^‐independent systems L and Ly^+^remained substantially unchanged. The density‐dependent change in activity of system A occurred through a mechanism affecting transport maximum (V~max~) rather than substrate concentration for half‐maximal velocity (K~m~). Transport activity of systems A and ASC was severalfold higher in transformed SV3T3 cells than in 3T3 parental cells at all the culture densities that could be compared. In SV3T3 revertant cells, transport activity by these systems remained substantially similar to that observed in transformed SV3T3 cells. The results presented here add cell density as a regulatory factor of the activity of systems A and ASC, and show that this control mechanism of amino acid transport is maintained in SV40 virus‐transformed 3T3 cells that have lost density‐dependent inhibition of growth, as well as in SV3T3 revertant cells that have resumed it.

📜 SIMILAR VOLUMES

2-Amino-isobutyric acid and 3-0-methyl-D
2-Amino-isobutyric acid and 3-0-methyl-D-glucose transport in 3T3, SV40-transformed 3T3 and revertant cell lines
✍ Robert Dubrow; Arthur B. Pardee; Robert Pollack 📂 Article 📅 1978 🏛 John Wiley and Sons 🌐 English ⚖ 848 KB

## Abstract In order to further investigate the connection between transport and growth control, 3T3 cells, SV40 transformed 3T3 cells (SV101), and three revertant cell lines derived from SV101 which have regained certain manifestations of growth control were used. Transport rates of 2‐aminoisobuty

Cholesterol levels and plasma membrane f
Cholesterol levels and plasma membrane fluidity in 3T3 and SV101-3T3 cells
✍ Scandella, Carl J. ;Hayward, James A. ;Lee, Nancy 📂 Article 📅 1979 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 339 KB

Polyene antibiotics such as filipin selectively inhibit wheat germ agglutinin-induced agglutination of transformed and malignant cells compared to normal cells (Hatten ME, Burger MM: Biochemistry 18: 739, 1979). Since filipin binds specifically to cholesterol, we measured cholesterol levels in 3T3 c

Transport of amino acids in intact 3T3 a
Transport of amino acids in intact 3T3 and SV3T3 cells. Binding activity for leucine in membrane preparations of ehrlich ascites tumor cells
✍ Cecchini, Gary ;Lee, Mary ;Oxender, Dale L. 📂 Article 📅 1976 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 315 KB

## Abstract Transport of amino acids into 3T3 and SV3T3 (SV40 virus‐transformed 3T3) cells was measured on glass cover slips. The 3T3 and SV3T3 cells contain both A (alanine preferring) and L (leucine preferring) systems for neutral amino acid transport. Initial rates of uptake of amino acids are a

The binding and processing of plasminoge
The binding and processing of plasminogen by Balb/c 3T3 and SV3T3 cells
✍ Jerry Tobler; Monty Krieger; Robert M. Stroud 📂 Article 📅 1981 🏛 John Wiley and Sons 🌐 English ⚖ 989 KB

## Abstract The binding and processing of plasminogen by Balb/c 3T3 and SV3T3 cells was studied using ^125^I‐labeled canine plasminogen. Throughout a 3‐day period, ^125^I‐plasminogen in the incubation medium bound to the cells and was degraded, first to intermediate‐sized macromolecules that were t

Age-dependent decrease of growth respons
Age-dependent decrease of growth responsiveness in density inhibited 3T3 cell populations and their interactions with SV 40-3T3 cells
✍ Jürgen van Der Bosch 📂 Article 📅 1980 🏛 John Wiley and Sons 🌐 English ⚖ 754 KB

## Abstract An aging process has been detected in stationary 3T3 cell cultures, especially in the presence of plasma‐derived serum (PDS) from adult bulls. It leads to irreversible conversion of an increasing percentage of initially responsive cells of a stationary population into cells unresponsive

Isolation and characterization of revert
Isolation and characterization of revertant cell lines. III. Isolation of density-revertants of SV40-transformed 3T3 cells using colchicine
✍ A. Vogel; R. Risser; R. Pollack 📂 Article 📅 1973 🏛 John Wiley and Sons 🌐 English ⚖ 602 KB

## Abstract Treatment of the SV40 transformed 3T3 cell line SV101 with colchicine permits the isolation of polyploid revertant sublines Which have lower saturation densities than SV101. These low saturation density lines have also reverted to a high serum requirement for growth, and are unable to f