cDNA cloning and analysis of a flg variant fibroblast growth factor receptor from Xenopus laevis

Chen, Gang (1993) cDNA cloning and analysis of a flg variant fibroblast growth factor receptor from Xenopus laevis. Masters thesis, Memorial University of Newfoundland.

[English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (17MB) [English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. (Original Version)

Abstract

1. A cDNA library was constructed with mRNA isolated from stage 8 Xenopus embryos. -- 2. A full length cDNA clone encoding a FGFR-1/flg gene was isolated by screening this cDNA library. It is designated XFGFR-A3. -- 3. The XFGFR-A3 clone was sequenced by dideoxynucleotide chain termination method on both strands with synthetic oligonucleotides. It is 3863 bp in length and is predicted to encode an 810 aa protein. -- 4. The XFGFR-A3 clone contains two dipeptide deletions, Val⁴²³⁻ Thr⁴²⁴ and Pro⁴⁴¹Ser⁴⁴², which are different from the published XFGFR-1 sequence ( Figure 8 ) . The Pro⁴⁴¹Ser⁴⁴² deletion has been described previously, however, this is the first report of the Val⁴²³⁻Thr⁴²⁴ deletion in Xenopus. Both dipeptide deletions result in the removal of consensus phosphorylation sites for Protein Kinase C ( PKC ) which may have consequences on intracellular signal transduction and the regulation of embryonic development. -- 5. RT-PCR results showed that XFGFR-A3 was expressed at all stages of Xenopus embryonic development. -- 6. The RNase protection experiment showed that XFGFR-A3 is a minor form of the XFGFR-1 in all stages of Xenopus embryonic development. Like the wild type XFGFR-1, XFGFR-A3 is also uniformly expressed throughout Xenopus development. -- 7. The XFGFR-A3 genomic DNA sequence covering the VT deletion region was sequenced. The VT deletion is located at an exon/intron boundary and comparison with the cDNA sequence suggests that the XFGFR-A3 variant arises from the use of an alternate 5'splice donor site. -- 8. Expression vectors containing an insert covering the VT deletion region fused to the cDNA encoding GST were constructed by using XFGFR-A2 and XFGFR-A3. A PKC assay using the purified fusion proteins products showed that Thr⁴²⁴ of XFGFR-A2 can be phosphorylated by PKC in vitro.

Actions (login required)

View Item