PTP gene family

Members of the PTP (protein tyrosine phosphatases) family help remove a phosphate group, a cluster of one phosphorus and three oxygen atoms, from other proteins. Specifically, these enzymes target an amino acid called tyrosine, which is one of the building blocks used to make proteins. Removal of a phosphate group from tyrosines modifies the activity of a protein. Based on the action of removing phosphate groups, these proteins are called phosphatases.

Through their phosphatase function, PTP proteins play a role in regulating a process called signal transduction. In signal transduction, the protein relays signals from outside the cell to the cell nucleus. These signals instruct the cell to grow and divide or to mature and take on specialized functions.

When mutated, some PTP proteins are associated with various types of cancers, such as colorectal, lung, breast, and gastric cancers, and some leukemias. The mutations associated with cancers are somatic mutations, meaning they are not inherited and are not passed on to the next generation. Two examples of PTP genes that normally help regulate cell growth and division, but when mutated can lead to various cancers, are the PTEN and PTPN11 genes.

The PTP gene family is sometimes referred to as a superfamily, meaning that genes belonging to the superfamily can be further categorized into smaller subfamilies. The PTP superfamily has four such subfamilies categorized according to the function and structure of the proteins the genes produce.