Abstract
Radiation-induced gene expression was examined in rat astrocyte cultures using differential display of mRNA via reverse transcriptase-polymerase chain reaction. A 0.3-kb cDNA that was consistently observed in irradiated cultures but not in unirradiated cultures was cloned and sequenced. It was found to be identical to Ptk-3, a receptor tyrosine kinase gene identified recently. The protein encoded by Ptk-3 is a member of a novel class of receptor tyrosine kinases whose extracellular domain contains regions of homology with coagulation factors V and VIII and complement component C1. Northern blot analysis revealed that the expression of Ptk-3 was increased in rat astrocytes by 0.5 h after exposure to 10 Gy and remained at the same elevated level for at least 24 h. The maximum increase occurred after 5 Gy. Cloning studies indicated the presence of at least two Ptk-3 mRNA transcripts, which are probably the result of an alternative splicing mechanism. The short isoform lacks a 37-amino acid sequence in the glycine/proline-rich juxtamembrane region. The splicing pattern of the Ptk-3 gene was not altered by radiation. However, the ratios of the longer to the shorter mRNA transcripts differed between adult cortex, neonatal cortex and in vitro astrocyte cultures.
Original language | English |
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Pages (from-to) | 1-7 |
Number of pages | 7 |
Journal | Radiation Research |
Volume | 143 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1995 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Biophysics
- Radiation
- Radiology Nuclear Medicine and imaging