PMID- 2498338
OWN - NLM
STAT- MEDLINE
DCOM- 19890713
LR  - 20210318
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 264
IP  - 17
DP  - 1989 Jun 15
TI  - Identification of a selenocysteyl-tRNA(Ser) in mammalian cells that recognizes 
      the nonsense codon, UGA.
PG  - 9724-7
AB  - The presence of a unique opal suppressor seryl-tRNA in higher vertebrates which 
      is converted to phosphoseryl-tRNA has been known for several years, but its 
      function has been uncertain (see Hatfield, D. (1985) Trends Biochem. Sci. 10, 
      201-204 for review). In the present study, we demonstrate that this tRNA species 
      also occurs in vivo as selenocysteyl-tRNA(Ser) suggesting that it functions both 
      as a carrier molecule upon which selenocysteine is synthesized and as a direct 
      selenocysteine donor to a growing polypeptide chain in response to specific UGA 
      codons. [75Se]Seleno[3H]cysteyl-tRNA(Ser) formed by administering 75Se and 
      [3H]serine to rat mammary tumor cells (TMT-081-MS) in culture was isolated from 
      the cell extract. The amino acid attached to the tRNA was identified as 
      selenocysteine following its deacylation and reaction with iodoacetate and 
      3-bromopropionate. The resulting alkyl derivatives co-chromatographed on an amino 
      acid analyzer with authentic carboxymethylselenocysteine and 
      carboxyethylselenocysteine. Seryl-tRNA(Ser) and phosphoseryl-tRNA(Ser) (Hatfield, 
      D., Diamond, A., and Dudock, B. (1982) Proc. Natl. Acad. Sci. U. S. A. 79, 
      6215-6219), which co-migrate on a reverse phase chromatographic column with 
      selenocysteyl-tRNA(Ser), were also identified in extracts of TMT-018-MS cells. 
      Hence, we propose that a metabolic pathway for selenocysteine synthesis in 
      mammalian cells is the conversion of seryl-tRNA(Ser) via phosphoseryl-tRNA(Ser) 
      to selenocysteyl-tRNA(Ser). In a ribosomal binding assay selenocysteyl-tRNA(Ser) 
      recognizes UGA but not any of the serine codons. Selenocysteyl-tRNA(Ser) is 
      deacylated more readily than seryl-tRNA(Ser) (i.e. 58% deacylation during 15 min 
      at pH 8.0 and 37 degrees C as compared to 41%).
FAU - Lee, B J
AU  - Lee BJ
AD  - Laboratory of Experimental Carcinogenesis, National Cancer Institute, Bethesda, 
      Maryland 20892.
FAU - Worland, P J
AU  - Worland PJ
FAU - Davis, J N
AU  - Davis JN
FAU - Stadtman, T C
AU  - Stadtman TC
FAU - Hatfield, D L
AU  - Hatfield DL
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Codon)
RN  - 0 (RNA, Messenger)
RN  - 0 (RNA, Transfer, Amino Acyl)
RN  - 0 (RNA, Transfer, Ser)
RN  - 0 (Selenium Radioisotopes)
RN  - 0 (selenocysteinyl-tRNA)
RN  - 10028-17-8 (Tritium)
RN  - 452VLY9402 (Serine)
RN  - F6A27P4Q4R (Selenious Acid)
RN  - H6241UJ22B (Selenium)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - Cell Line
MH  - *Codon
MH  - Mammary Neoplasms, Experimental/metabolism
MH  - *RNA, Messenger
MH  - RNA, Transfer, Amino Acyl/*genetics/isolation & purification/metabolism
MH  - RNA, Transfer, Ser/genetics/metabolism
MH  - Rats
MH  - Ribosomes/metabolism
MH  - Selenious Acid
MH  - Selenium/metabolism
MH  - Selenium Radioisotopes
MH  - Serine/metabolism
MH  - Tritium
EDAT- 1989/06/15 00:00
MHDA- 1989/06/15 00:01
CRDT- 1989/06/15 00:00
PHST- 1989/06/15 00:00 [pubmed]
PHST- 1989/06/15 00:01 [medline]
PHST- 1989/06/15 00:00 [entrez]
AID - S0021-9258(18)81714-8 [pii]
PST - ppublish
SO  - J Biol Chem. 1989 Jun 15;264(17):9724-7.