The 29 nucleotide insertion/deletion polymorphism is 2214 nts upstream from the PDE3A1 translation start site
that regulates transcriptional activity in response to cyclic adenosine monophosphate, or cAMP, levels, with the insertion, or INS, allele having a frequency of 0.41.
The 5'-end sequence of SPRP was obtained from a longer cDNA clone (SPRP2, accession number AF331852), containing 99 bp of 5' noncoding sequence with one possible translation start site (ATG).
A total of 1.8 kb of upstream sequence from the translation start site of SPRP1 was sequenced from this clone (Accession number AF331851).
A cDNA clone (Accession number AF331850) isolated during library screening was close to full length with the 5' end being 18 bp downstream of the ATG translation start site. The sugarcane SEF1[alpha] clone shows 93% similarity to the maize nucleotide sequence and 99% similarity to the maize deduced amino acid sequence (Berberich et al., 1995), respectively.
To map the 5' end of the SEF1[alpha] gene, a primer extension reaction was done with a 30-bp primer near the translation start site. On the basis of manual sequencing of the genomic clone, the transcription start site (tsp) is 130 bp upstream of the translation start site (excluding the intron located in the 5' UTR).
'The finding of alternative translation start sites
within this important group of proteins adds startling diversity to a key biological process, namely that whereby heart cells communicate with each other electrically," explains Eduardo Marban, director of Cedars-Sinai.