Neuron-specific splicing of C-SRC RNA in human brain

Area of Science:

• Molecular Biology
• Neuroscience
• Genetics

Background:

• The C-SRC, C-YES, and FYN genes encode closely related tyrosine protein kinases found in human neural tissues.
• A neuronal-specific splice variant of C-SRC, adding an 18 base pair exon, is known in avian and murine brains.
• C-YES and FYN share similar exon-intron boundaries and homology with C-SRC in the exon 3/4 region, but their alternative splicing patterns were uninvestigated.

Purpose of the Study:

• To compare the expression patterns of C-SRC, C-YES, and FYN RNAs across different human tissues.
• To investigate potential alternative splicing of C-YES and FYN in the exon 3/4 region.
• To determine if human C-SRC exhibits neuronal-specific splicing similar to avian and murine models.

Main Methods:

• RNA expression analysis in human lung, liver, brain, and placenta.
• Preparation of cDNA clones spanning exons 3 and 4 for C-SRC, C-YES, and FYN.
• Sequence analysis of cDNA clones to identify alternative splicing events.

Main Results:

• FYN and C-YES RNA splicing patterns were consistent across all examined human tissues.
• Human brain-derived C-SRC cDNAs contained an additional 18 base pairs within the analyzed region.
• This addition in human C-SRC corresponds to a six amino acid sequence identical to that found in avian and murine neural-specific C-SRC variants.

Conclusions:

• Human C-SRC gene exhibits neuronal-specific alternative splicing, mirroring findings in avian and murine species.
• This specific splicing event adds a conserved six-amino acid sequence in the brain.
• Unlike C-SRC, the C-YES and FYN genes do not appear to undergo similar alternative splicing in the investigated exon region across human tissues.