CCHC-type zinc finger nucleic acid binding protein
The CNBP gene provides instructions for making a protein called CCHC-type zinc finger nucleic acid binding protein. This protein has seven regions, called zinc finger domains, which are thought to attach (bind) to specific sites on DNA and its chemical cousin, RNA.
The CNBP protein is found in many of the body's tissues, but it is most abundant in the heart and in muscles used for movement (skeletal muscles). The CNBP protein regulates the activity of other genes and is necessary for normal development before birth, particularly of muscles.
One region of the CNBP gene contains a segment of four DNA building blocks (nucleotides) that is repeated multiple times. This sequence, which is written as CCTG, is called a tetranucleotide repeat. In most people, the CCTG sequence is repeated fewer than 26 times.
Mutations in the CNBP gene cause a form of myotonic dystrophy known as myotonic dystrophy type 2. Myotonic dystrophy is characterized by progressive muscle wasting and weakness. Muscle weakness in type 2 primarily involves muscles close to the center of the body (proximal muscles), such as the those of the neck, shoulders, elbows, and hips. People with this disorder often have prolonged muscle contractions (myotonia) and are not able to relax certain muscles after use.
The type of gene mutation that causes myotonic dystrophy type 2 is known as a tetranucleotide repeat expansion. This mutation increases the size of the repeated CCTG segment in the CNBP gene. People with myotonic dystrophy type 2 have from 75 to more than 11,000 CCTG repeats.
The mutated CNBP gene produces an altered version of messenger RNA, which is a molecular blueprint of the gene that guides the production of proteins. Researchers have found that the altered messenger RNA traps proteins to form clumps within the cell. The clumps interfere with the production of many other proteins. These changes prevent muscle cells and cells in other tissues from functioning properly, leading to muscle weakness and the other features of myotonic dystrophy type 2.
- CCHC-type zinc finger, nucleic acid binding protein
- cellular nucleic acid binding protein
- cellular retroviral nucleic acid-binding protein 1
- zinc finger 9 protein
- zinc finger protein 9
- zinc finger protein 9 (a cellular retroviral nucleic acid binding protein)
- zinc finger protein 273