Transactivation of a human cytomegalovirus early promoter by gene products from the immediate-early gene IE2 and augmentation by IE1: Mutational analysis of the viral proteins

TY - JOUR

T1 - Transactivation of a human cytomegalovirus early promoter by gene products from the immediate-early gene IE2 and augmentation by IE1

T2 - Mutational analysis of the viral proteins

AU - Malone, Cheryl L.

AU - Vesole, David H.

AU - Stinski, Mark F.

PY - 1990

Y1 - 1990

N2 - Expression from a human cytomegalovirus early promoter (El .7) has been shown to be activated in trans by the IE2 gene products (C.-P. Chang, C. L. Malone, and M. F. Stinski, J. Virol. 63:281-290, 1989). Using wild-type and mutant viral proteins, we have defined the protein regions required for transactivation of the El.7 promoter in IE2 and for augmentation of transactivation in the IE1 protein. Two regions of the IE2 proteins were found to be essential for transactivation. One near the amino terminus is within 52 amino acids encoded by exon 3. The second comprises the carboxyl-terminal 85 amino acids encoded by exon 5. The IE2 protein encoded by an mRNA which lacks the intron within exon 5 and the IE2 protein encoded by exon 5 had no activity for transactivation of the E1.7 promoter. Although the IE1 gene product alone had no effect on this early viral promoter, maximal early promoter activity was detected when both IE1 and IE2 gene products were present. The IE1 protein positively regulated its enhancer-containing promoter-regulatory region. The IE1 protein alone increased the steady-state level of IE2 mRNA; therefore, IE1 and IE2 are synergistic for expression from the E1.7 promoter. Like the IE2 proteins, the IE1 protein requires for activity 52 amino acids encoded by exon 3. IE1 also requires amino adds encoded by exon 4. Since the IE1 and IE2 proteins have 85 amino acids in common at the amino-terminal end encoded by exons 2 and 3, the difference between these specific transactivators resides in their carboxyl-terminal amino acids encoded by exons 4 and 5, respectively.

AB - Expression from a human cytomegalovirus early promoter (El .7) has been shown to be activated in trans by the IE2 gene products (C.-P. Chang, C. L. Malone, and M. F. Stinski, J. Virol. 63:281-290, 1989). Using wild-type and mutant viral proteins, we have defined the protein regions required for transactivation of the El.7 promoter in IE2 and for augmentation of transactivation in the IE1 protein. Two regions of the IE2 proteins were found to be essential for transactivation. One near the amino terminus is within 52 amino acids encoded by exon 3. The second comprises the carboxyl-terminal 85 amino acids encoded by exon 5. The IE2 protein encoded by an mRNA which lacks the intron within exon 5 and the IE2 protein encoded by exon 5 had no activity for transactivation of the E1.7 promoter. Although the IE1 gene product alone had no effect on this early viral promoter, maximal early promoter activity was detected when both IE1 and IE2 gene products were present. The IE1 protein positively regulated its enhancer-containing promoter-regulatory region. The IE1 protein alone increased the steady-state level of IE2 mRNA; therefore, IE1 and IE2 are synergistic for expression from the E1.7 promoter. Like the IE2 proteins, the IE1 protein requires for activity 52 amino acids encoded by exon 3. IE1 also requires amino adds encoded by exon 4. Since the IE1 and IE2 proteins have 85 amino acids in common at the amino-terminal end encoded by exons 2 and 3, the difference between these specific transactivators resides in their carboxyl-terminal amino acids encoded by exons 4 and 5, respectively.

UR - https://www.scopus.com/pages/publications/0025260745

M3 - Article

C2 - 2157038

SN - 0022-538X

VL - 64

SP - 1498

EP - 1506

JO - Journal of virology

JF - Journal of virology

IS - 4

ER -