pThr133Arg

pThr133Arg refers to a specific post-translational modification and its resulting amino acid substitution within a protein. Specifically, it indicates a change where a threonine residue at position 133 of a protein is phosphorylated, and then subsequently this phosphorylation is replaced by an arginine residue through an amino acid substitution.

Phosphorylation is a common regulatory mechanism in proteins, where a phosphate group is added to a threonine, serine, or tyrosine residue. This modification can alter the protein's structure, activity, or interactions with other molecules. In the case of pThr133Arg, the initial state involves a phosphorylated threonine at position 133.

The subsequent "Arg" part signifies a genetic mutation or a change in the protein sequence itself, where the original threonine at position 133 has been replaced by an arginine. This means that even without phosphorylation, the amino acid at this position is now arginine.

The combined notation pThr133Arg is often used in scientific literature to denote a situation where a specific site is known to be phosphorylated (pThr) and also harbors a mutation that changes the residue to arginine (Arg) at that same position. This can be significant for understanding protein function, as the arginine substitution might mimic or abolish the effects of phosphorylation, or have its own distinct functional consequences. The precise biological implications of pThr133Arg would depend heavily on the specific protein and its role in cellular processes.