Question

Tau is a microtubule-associated protein that plays a key role in the development of certain brain disorders. To analyze Tau expression, mouse brain extracts are made at different developmental stages, separated on an SDS-PAGE gel, and analyzed by western blot with antibodies recognizing only mouse Tau protein. If the results at the right represent Tau’s normal expression pattern, the two different size protein products could result from:
1. transcription of Tau DNA in different directions.
2. translation of Tau mRNAs of different sizes.
3. expression of two different genes.
4. different chemical modifications of Tau protein.

Answer 1

Answer:

1. transcription of Tau DNA in different directions.

4. different chemical modifications of Tau protein.

Explanation:

Tau gene transcribe in different direction which depends upon the animal age. This happens because at different age and developmental stage, animal produce different RNA binding proteins which leads to formation of alternative splice forms. This reaction is strengthen by the addition of phosphate and sugar molecules which again depending on developmental stage and time.