Worm Breeder's Gazette 16(5): 31 (February 1, 2001)

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Characterization of rcn-1, a calcipressin homologue in C. elegans

Jin Lee1, Jaya Bandyopadhyay1, Tami Kingsbury2, Kyle Cunningham2, Joohong Ahnn1

1 Department of Life Sciences, Kwangju Institute of Science and Technology, , Kwangju 500-712, Korea
2 Department of Biology, Johns Hopkins University, Baltimore, MD 21218

     Calcipressins are a family of calcineurin regulating proteins
conserved from fungi to yeast to man.  They show binding, inhibiting,
and even transcription regulation of the calcium/calmodulin phosphatase
calcineurin, and also may play a role in Down Syndrome in humans.  A
calcipressin homologue, rcn-1, has been identified in C. elegans on
chromosome III in cosmid F54E7.
     A 3.1 kb upstream region of the genomic DNA of rcn-1 was cloned
into a GFP vector and expression was seen in wild-type worms. 
Expression was seen mainly in pharyngeal muscle, excretory cells, vulval
epithelial cells, ventral and dorsal nerve cords and commissures, head
sensory neurons, nerve ring, pre-anal and tail neurons and to a lesser
extent in hypodermal cells and intestine. High neuronal and pharyngeal
muscle expression is consistent with highly expressed levels of the
human homologue DSCR-1 (Down Syndrome Critical Region) in heart and
brain in mammals.
     Polyclonal antibodies were raised against the conserved region of
DSCR-1 (Down Syndrome Critical Region ), a human homologue of rcn-1 in
rabbit, and immunostaining with these antibodies was performed in C.
elegans.  We were able to observe expression in excretory cells, vulval
epithelial cells, ventral and dorsal nerve cords and commissures, head
sensory neurons, nerve ring, tail neurons, and hypodermal cells. This
expression not only confirms our previous GFP expression results, but
also shows the conservation of calcipressins from humans to C. elegans. 
Preliminary data of calcineurin GFP and antibody expression from our
laboratory has shown much overlap of expression between rcn-1 and
calcineurin showing a possible relationship between the two proteins. 
We hope to further delineate this relationship by biochemical analysis
of the two proteins.  Currently, we are also preparing to raise
antibodies against rcn-1 in rabbit.
     Northern blot analysis has confirmed a low-level of expression of a
1.0 kb mRNA transcript.  We are planning to conduct RNAi of rcn-1 and
will try to obtain deletion mutants by UV-TMP mutagenesis to observe