Publication Date:
1991-12-13
Description:
Guanosine triphosphatase (GTPase) activity of Ras is increased by interaction with Ras-GAP (GTPase-activating protein) or with the GAP-related domain of the type 1 neurofibromatosis protein (NF1-GRD), but Ras is not affected by interaction with cytoplasmic and membrane forms of Rap-GAP; Rap1A, whose effector function can suppress transformation by Ras, is sensitive to both forms of Rap-GAP and resistant to Ras-GAP and NF1-GRD. A series of chimeric proteins composed of portions of Ras and Rap were constructed; some were sensitive to Ras-GAP but resistant to NF1-GRD, and others were sensitive to cytoplasmic Rap-GAP but resistant to membrane Rap-GAP. Sensitivity of chimeras to Ras-GAP and cytoplasmic Rap-GAP was mediated by amino acids that are carboxyl-terminal to the effector region. Residues 61 to 65 of Ras conferred Ras-GAP sensitivity, but a larger number of Rap1A residues were required for sensitivity to cytoplasmic Rap-GAP. Chimeras carrying the Ras effector region that were sensitive only to Ras-GAP or only to cytoplasmic Rap-GAP transformed NIH 3T3 cells poorly. Thus, distinct amino acids of Ras and Rap1A mediate sensitivity to each of the proteins with GAP activity, and transforming potential of Ras and sensitivity of Ras to Ras-GAP are at least partially independent properties.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, K -- Papageorge, A G -- Martin, P -- Vass, W C -- Olah, Z -- Polakis, P G -- McCormick, F -- Lowy, D R -- New York, N.Y. -- Science. 1991 Dec 13;254(5038):1630-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Cellular Oncology, National Cancer Institute, Bethesda, MD 20892.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1749934" target="_blank"〉PubMed〈/a〉
Keywords:
Cell Membrane/metabolism
;
Cytosol/metabolism
;
Enzyme Activation
;
GTP-Binding Proteins/*physiology
;
GTPase-Activating Proteins
;
Genes, Neurofibromatosis 1
;
In Vitro Techniques
;
Proteins/*physiology
;
Proto-Oncogene Proteins p21(ras)/*physiology
;
Recombinant Fusion Proteins
;
Structure-Activity Relationship
;
rap GTP-Binding Proteins
;
ras GTPase-Activating Proteins
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
