FPGT-TNNI3K gene: function, expression, and disease relevance

FPGT-TNNI3K is a naturally occurring readthrough gene located on chromosome 1p31.1. It is formed by the fusion of the FPGT (fucose-1-phosphate guanylyltransferase) and TNNI3K (TNNI3 interacting kinase) genes, producing a single transcript that encodes a protein with domains from both parental proteins. The readthrough event results in a protein that retains the kinase domain of TNNI3K and the transferase domain of FPGT, potentially linking metabolic and signaling functions. This gene is expressed in various tissues, with notable levels in the heart and skeletal muscle, and has been implicated in cardiac function and cancer progression.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• MAPK signaling pathway

• Cardiac muscle contraction

• Fucose metabolism

The FPGT-TNNI3K readthrough protein is a fusion of fucose-1-phosphate guanylyltransferase (FPGT) and TNNI3 interacting kinase (TNNI3K). It contains an N-terminal FPGT domain involved in fucose metabolism and a C-terminal kinase domain that phosphorylates cardiac troponin I (TNNI3) and other substrates. The protein is predominantly expressed in cardiac and skeletal muscle, where it may regulate myocyte function and survival. In cancer, aberrant expression of the readthrough transcript has been observed, suggesting a potential role in tumorigenesis through kinase signaling and metabolic reprogramming. However, functional studies are limited, and further research is needed to clarify its physiological and pathological roles.