p73 Alternative Splicing: Exploring a Biological Role for the C-Terminal Isoforms

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• The p73 protein (encoded by the TP73 gene) is structurally and functionally related to p53.
• p73 plays roles in DNA damage response, cell cycle arrest, and apoptosis, similar to p53.
• p73 also has critical non-tumor-related functions, including neurological development, ciliogenesis, and fertility.

Purpose of the Study:

• To review and unify the current literature on p73 C-terminal isoforms and the role of the sterile alpha motif (SAM) domain.
• To highlight the complexity arising from p73's N-terminally deleted and alternatively spliced C-terminal isoforms.
• To emphasize the need for further research into the functional differences of p73 C-terminal splice variants.

Main Methods:

• Literature review and synthesis of existing data on p73 isoforms and function.
• Analysis of structural features, including the sterile alpha motif domain.
• Discussion of spatio-temporal expression patterns and functional studies.

Main Results:

• p73 exhibits complex regulation through N-terminal deletions (TAp73, ΔNp73) and alternative C-terminal splicing.
• The functional significance of distinct p73 C-terminal splice forms remains largely undefined.
• Full-length TAp73α appears to be the predominant isoform in physiological systems.

Conclusions:

• The diverse roles of p73, particularly its non-tumorigenic functions, are influenced by its complex isoform expression.
• Current understanding of p73 C-terminal isoforms and the SAM domain's contribution is limited.
• Further detailed spatio-temporal and functional studies are crucial to elucidate the physiological relevance of p73 alternative splicing.