Growth suppressor that facilitates the entry of the cell into cell cycle arrest. Functionally similar to the retinoblastoma protein it binds to and represses the activity of cell-cycle-promoting proteins such as SV40 large T antigen, adenovirus E1A, and the transcription factor E2F. Necdin also interacts with p53 and works in an additive manner to inhibit cell growth. Also functions as a transcription factor and directly binds to specific guanosine-rich DNA sequences (By similarity). Binds to the transactivation domains of E2F1 and p53. Binds also SV40 large T antigen and adenovirus E1A. Interacts with nucleobindin 1 and 2 (By similarity). Neural perikarya, translocates to the nucleus of postmitotic neurons and interacts with the nuclear matrix. Almost ubiquitous. Detected in fetal brain, lung, liver and kidney; in adult heart, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas, spleen, thymus, prostate, testis, ovary, small intestine and colon. Not detected in peripheral blood leukocytes. In brain, restricted to post-mitotic neurons. Located in the Prader-Willi syndrome (PWS) chromosome region. Prader-Willi syndrome is a contiguous gene syndrome resulting from deletion of the paternal copies of the imprinted SNRPN gene, the necdin gene, and possibly other genes within the chromosome region 15q11-q13.