Abstract
We previously reported that a melanoma antigen, recognized by tumor- specific cytotoxic T lymphocytes, was encoded by intron sequences retained in a partially spliced transcript of the tyrosinase-related protein-2/DOPAchrome tautomerase gene. At difference with the mRNA encoding tyrosinase-related protein-2, this anomalous transcript was not expressed in melanocytes. This study examined whether neoplastic and/or normal cells of the melanocytic lineage could express additional forms of tyrosinase-related protein-2 mRNA. Screening of a melanoma-derived cDNA library with a tyrosinase-related protein-2 probe allowed identification of two novel isoforms. The first, tyrosinase-related protein-2-long tail, corresponds to the dominant transcript detected on melanomas and melanocytes by northern blot analysis. Tyrosinase-related protein-2-long tail is identical to the tyrosinase-related protein-2-encoding published cDNA sequence except for an extended 3'- untranslated region and is originated by alternative polyadenylation. This novel 3'-untranslated region contains an alternatively spliced, tyrosinase- related protein-2 last exon in the second isoform (tyrosinase-related protein-2-8b). The protein encoded by tyrosinase-related protein-2-8b is identical to tyrosinase-related protein-2 in its first 460 amino acids but possesses a different carboxyl-terminus devoid of transmembrane domain. Tyrosinase-related protein-2-long tail exhibited DOPA-chrome tautomerase activity, when transiently transfected into COS-7 cells. On the contrary, no detectable activity was exhibited by tyrosinase-related protein-2-8b. Reverse transcription-polymerase chain reaction analysis indicated that tyrosinase- related protein-2-long tail and tyrosinase-related protein-2-8b are expressed by tyrosinase-related protein-2-positive melanomas and normal melanocytes. Moreover all cell lines positive for tyrosinase-related protein-2 isoforms expressed tyrosinase and, all but one, tyrosinase-related protein-1. These data show that the human tyrosinase-related protein-2/DOPAchrome tautomerase gene can yield different isoforms by alternative poly(A) site usage or by alternative splicing. The pattern of expression of these isoforms suggest that they might play a part in the normal pathway of melanin biosynthesis.
| Original language | English |
|---|---|
| Pages (from-to) | 48-56 |
| Number of pages | 9 |
| Journal | Journal of Investigative Dermatology |
| Volume | 115 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2000 |
Fingerprint
Keywords
- Alternative polyadenylation
- Alternative splicing
- Melanoma antigens
- Pigmentation
ASJC Scopus subject areas
- Dermatology
Cite this
Human melanocytes and melanomas express novel mRNA isoforms of the tyrosinase-related protein-2/DOPAchrome tautomerase gene : Molecular and functional characterization. / Pisarra, Patrizia; Lupetti, Raffaella; Palumbo, Anna; Napolitano, Alessandra; Prota, Giuseppe; Parmiani, Giorgio; Anichini, Andrea; Sensi, Marialuisa.
In: Journal of Investigative Dermatology, Vol. 115, No. 1, 2000, p. 48-56.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Human melanocytes and melanomas express novel mRNA isoforms of the tyrosinase-related protein-2/DOPAchrome tautomerase gene
T2 - Molecular and functional characterization
AU - Pisarra, Patrizia
AU - Lupetti, Raffaella
AU - Palumbo, Anna
AU - Napolitano, Alessandra
AU - Prota, Giuseppe
AU - Parmiani, Giorgio
AU - Anichini, Andrea
AU - Sensi, Marialuisa
PY - 2000
Y1 - 2000
N2 - We previously reported that a melanoma antigen, recognized by tumor- specific cytotoxic T lymphocytes, was encoded by intron sequences retained in a partially spliced transcript of the tyrosinase-related protein-2/DOPAchrome tautomerase gene. At difference with the mRNA encoding tyrosinase-related protein-2, this anomalous transcript was not expressed in melanocytes. This study examined whether neoplastic and/or normal cells of the melanocytic lineage could express additional forms of tyrosinase-related protein-2 mRNA. Screening of a melanoma-derived cDNA library with a tyrosinase-related protein-2 probe allowed identification of two novel isoforms. The first, tyrosinase-related protein-2-long tail, corresponds to the dominant transcript detected on melanomas and melanocytes by northern blot analysis. Tyrosinase-related protein-2-long tail is identical to the tyrosinase-related protein-2-encoding published cDNA sequence except for an extended 3'- untranslated region and is originated by alternative polyadenylation. This novel 3'-untranslated region contains an alternatively spliced, tyrosinase- related protein-2 last exon in the second isoform (tyrosinase-related protein-2-8b). The protein encoded by tyrosinase-related protein-2-8b is identical to tyrosinase-related protein-2 in its first 460 amino acids but possesses a different carboxyl-terminus devoid of transmembrane domain. Tyrosinase-related protein-2-long tail exhibited DOPA-chrome tautomerase activity, when transiently transfected into COS-7 cells. On the contrary, no detectable activity was exhibited by tyrosinase-related protein-2-8b. Reverse transcription-polymerase chain reaction analysis indicated that tyrosinase- related protein-2-long tail and tyrosinase-related protein-2-8b are expressed by tyrosinase-related protein-2-positive melanomas and normal melanocytes. Moreover all cell lines positive for tyrosinase-related protein-2 isoforms expressed tyrosinase and, all but one, tyrosinase-related protein-1. These data show that the human tyrosinase-related protein-2/DOPAchrome tautomerase gene can yield different isoforms by alternative poly(A) site usage or by alternative splicing. The pattern of expression of these isoforms suggest that they might play a part in the normal pathway of melanin biosynthesis.
AB - We previously reported that a melanoma antigen, recognized by tumor- specific cytotoxic T lymphocytes, was encoded by intron sequences retained in a partially spliced transcript of the tyrosinase-related protein-2/DOPAchrome tautomerase gene. At difference with the mRNA encoding tyrosinase-related protein-2, this anomalous transcript was not expressed in melanocytes. This study examined whether neoplastic and/or normal cells of the melanocytic lineage could express additional forms of tyrosinase-related protein-2 mRNA. Screening of a melanoma-derived cDNA library with a tyrosinase-related protein-2 probe allowed identification of two novel isoforms. The first, tyrosinase-related protein-2-long tail, corresponds to the dominant transcript detected on melanomas and melanocytes by northern blot analysis. Tyrosinase-related protein-2-long tail is identical to the tyrosinase-related protein-2-encoding published cDNA sequence except for an extended 3'- untranslated region and is originated by alternative polyadenylation. This novel 3'-untranslated region contains an alternatively spliced, tyrosinase- related protein-2 last exon in the second isoform (tyrosinase-related protein-2-8b). The protein encoded by tyrosinase-related protein-2-8b is identical to tyrosinase-related protein-2 in its first 460 amino acids but possesses a different carboxyl-terminus devoid of transmembrane domain. Tyrosinase-related protein-2-long tail exhibited DOPA-chrome tautomerase activity, when transiently transfected into COS-7 cells. On the contrary, no detectable activity was exhibited by tyrosinase-related protein-2-8b. Reverse transcription-polymerase chain reaction analysis indicated that tyrosinase- related protein-2-long tail and tyrosinase-related protein-2-8b are expressed by tyrosinase-related protein-2-positive melanomas and normal melanocytes. Moreover all cell lines positive for tyrosinase-related protein-2 isoforms expressed tyrosinase and, all but one, tyrosinase-related protein-1. These data show that the human tyrosinase-related protein-2/DOPAchrome tautomerase gene can yield different isoforms by alternative poly(A) site usage or by alternative splicing. The pattern of expression of these isoforms suggest that they might play a part in the normal pathway of melanin biosynthesis.
KW - Alternative polyadenylation
KW - Alternative splicing
KW - Melanoma antigens
KW - Pigmentation
UR - http://www.scopus.com/inward/record.url?scp=0033939851&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033939851&partnerID=8YFLogxK
U2 - 10.1046/j.1523-1747.2000.00023.x
DO - 10.1046/j.1523-1747.2000.00023.x
M3 - Article
C2 - 10886507
AN - SCOPUS:0033939851
VL - 115
SP - 48
EP - 56
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
SN - 0022-202X
IS - 1
ER -