Non-AUG translational initiation of a short CAPC transcript generating  protein isoform.
CAPC (also known as LRRC26) is a new gene with restricted expression in normal tissues, and with expression in many cancers and cancer cell lines. We have identified and characterized a short-transcript of CAPC (S-CAPC). The nucleotide sequence analysis of CAPC mRNA showed that the transcription for S-CAPC starts at position +610 on the L-CAPC transcript. Interestingly, no translation initiation codon 'AUG' is present in this transcript. To determine if a non-AUG start site is utilized, the S-CAPC sequence was cloned into an expression vector with C-terminal myc and histidine tags, and transfected into 293T cells. Western blot and MALDI-TOF MS analysis on purified S-CAPC gave two distinct peaks at approximately 7.5 kDa. N-terminal amino acid sequencing of the purified 7.5 kDa protein product indicated that translation starts at the codon for cysteine on the S
Anaganti
Suresh
S
Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Room 5110, Bethesda, MD 20892-4264, USA.
Hansen
Johanna K
JK
Ha
Duc
D
Hahn
Yoonsoo
Y
Chertov
Oleg
O
Pastan
Ira
I
Bera
Tapan K
TK
D045744:Cell Line, Tumor; D018387:Codon, Initiator / Q000378:metabolism*; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism*; D010442:Peptide Chain Initiation, Translational; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D020539:Sequence Analysis, Protein; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014158:Transcription, Genetic
D018387:Codon, Initiator; C539913:LRRC26 protein, human; D009363:Neoplasm Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger