Immunochemical detection of proteins related to the human c-myc exon 1.

Abstract

Published sequence data of the human c‐myc gene indicate the presence of a coding capacity for a polypeptide of 188 residues within the first exon. Using antibodies raised against five synthetic peptides corresponding to different non‐over‐lapping parts of this polypeptide, two proteins of 32 kd and 58 kd antigenically related to the synthetic peptides have been detected in extracts of human cells. The confidence of this detection has been reinforced by showing that epitopes corresponding to different peptides were indeed located on the same molecule and that the 58 kd protein appears to be a dimeric form of the 32 kd protein. That these proteins originate from the first exon was indicated by: hybrid‐arrested translation experiments followed by immunodetection of the translation products; in vitro translation of messenger RNA derived from cloned exon 1 by SP6 polymerase transcription.

Alternative Translation of the Proto-oncogene c-mycby an Internal Ribosome Entry Site

“…Only the 188-amino acid product has been characterized in HeLa cells. The function of this MycHEX1 protein remains unknown, however (9). In contrast to the coding capacity of P0, P1, and P2 mRNAs, that of P3 mRNA is restricted to the 64-kDa c-Myc2 protein.…”

Poly(A) shortening and degradation of the 3' A+U-rich sequences of human c-myc mRNA in a cell-free system.

“…The c-myc gene products are nuclear phosphoproteins of unknown function (3,34,38,39,76). They are significant not only because they are related to a viral oncogene product (7,22,33,99,100) but also because they play a role in regulating cell growth and differentiation.…”

Induction of proliferation of neuroretina cells by long terminal repeat activation of the carboxy-terminal part of c-mil.

“…3B). A total of 106 cell lysates were prepared from each of the transfected NR cultures as previously described (12) and electrophoresed through a sodium dodecyl sulfate-10% polyacrylamide gel. The proteins were transferred to nitrocellulose and probed with the anti-v-mil antiserum (dilution, 1:100) described above.…”