K. Subramaniam et al., CLONING AND SEQUENCE OF A CDNA-ENCODING A NOVEL HYBRID PROLINE-RICH PROTEIN ASSOCIATED WITH CYTOKININ-INDUCED HAUSTORIA FORMATION IN CUSCUTA-REFLEXA, Gene, 141(2), 1994, pp. 207-210
A complete cDNA encoding a novel hybrid Pro-rich protein (HyPRP) was i
dentified by differentially screening 3x10(4) recombinant plaques of a
Cuscuta reflexa cytokinin-induced haustorial cDNA library constructed
in lambda gt10. The nucleotide (nt) sequence consists of: (i) a 424-b
p 5'-non coding region having five start codons (ATGs) and three upstr
eam open reading frames (uORFs); (ii) an ORF of 987 bp with coding pot
ential for a 329-amino-acid (aa) protein of M(r), 35203 with a hydroph
obic N-terminal region including a stretch of nine consecutive Phe fol
lowed by a Pro-rich sequence and a Cys-rich hydrophobic C terminus; an
d (iii) a 178-bp 3'-UTR (untranslated region). Comparison of the predi
cted aa sequence with the NBRF and SWISSPROT databases and with a rece
nt report of an embryo-specific protein of maize [Jose-Estanyol et al.
, Plant Cell 4 (1992) 413-423] showed it to be similar to the class of
HyPRPs encoded by genes preferentially expressed in young tomato frui
ts, maize embryos and in vitro-cultured carrot embryos. Northern analy
sis revealed an approx. 1.8-kb mRNA of this gene expressed in the suba
pical region of the C. reflexa vine which exhibited maximum sensitivit
y to cytokinin in haustorial induction.