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L Conroy

Publications and source records attributed to L Conroy.

25 records · Page 2Linked to original sources

Molecular cloning of a GTPase activating protein specific for the Krev-1 protein p21rap1.

The rap1/Krev-1 gene encodes a ras-related protein that suppresses transformation by ras oncogenes. We have purified an 88 kd GTPase activating protein (GAP), specific for the rap1/Krev-1 gene product, from bovine brain. Based on partial amino acid sequences obtained from this protein, a 3.3 kb cDNA was isolated from a human brain library. Expression of the cDNA in insect Sf9 cells resulted in high level production of an 85-95 kd rap1GAP that specifically stimulated the GTPase activity of p21rap1. The complete deduced amino acid sequence is not homologous to any known protein sequences, including GAPs specific for p21ras. Northern and Western blotting analysis indicate that rap1GAP is not ubiquitously expressed and appears most abundant in fetal tissues and certain tumor cell lines, particularly the Wilms' kidney tumor, SK-NEP-1, and the melanoma, SK-MEL-3, cell lines.

Amino Acid Sequence↗

The GAP-related domain of the neurofibromatosis type 1 gene product interacts with ras p21.

The neurofibromatosis type 1 (NF1) protein contains a region of significant sequence similarity to ras p21 GTPase-activating protein (GAP) and the yeast IRA1 gene product. A fragment of NF1 cDNA encoding the GAP-related domain (NF1 GRD) was expressed, immunoaffinity purified, and assayed for effects on N-ras p21 GTPase activity. The GTPase of wild-type ras p21 was stimulated by NF1 GRD, but oncogenic mutants of ras p21 (Asp-12 and Val-12) were unaffected, and the GTPase of an effector mutant (Ala-38) was only weakly stimulated. NF1 GRD also down-regulated RAS function in S. cerevisiae. The affinity of NF1 GRD for ras p21 was estimated to be 250 nM: this is more than 20-fold higher than the affinity of GAP for ras p21. However, its specific activity was about 30 times lower. These kinetic measurements suggest that NF1 may be a significant regulator of ras p21 activity, particularly at low ras p21 concentrations.

Amino Acid Sequence↗

Testicular yolk sac carcinoma in infants: natural history in 56 consecutive patients.

Fifty six patients with yolk sac tumor are registered in the "Instituto Nacional de Enfermedades Neoplásicas" (Lima-Peru), from 1952-1980: 48.22% were less than 2 years of age; 51.78% were beyond that age.- Seventeen patients survived 3 years post diagnosis: 44% when patients less than 2 years of age and 17.2% when over two years of age. 25.9% of the patients less than 2 years of age were found to have metastases whereas 48.5% when over 2 years of age. 21/56 already had metastases when first seen. All tumors were greater than or equal to 3 cm. in diameter when first seen. Metastases were found in 38% of cases when tumors were less than or equal to 6 cm., compared to 61.9% of cases in which tumors exceeded 6 cm. 51.8% of clinical stage I survived 3 years without evidence of disease; 14.3% when stage II while none survived at clinical stage IV. It is to be expected that young patients who survive 3 years after diagnosis and treatment will not suffer a recurrence of the disease.

Adolescent↗

Storytelling at work.

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Education, Nursing↗