PT  - JOURNAL ARTICLE
AU  - Timothy R. Gershon
AU  - Michael W. Baker
AU  - Michael Nitabach
AU  - Peter Wu
AU  - Eduardo R. Macagno
TI  - Two Receptor Tyrosine Phosphatases of the LAR Family Are Expressed in the Developing Leech by Specific Central Neurons as well as Select Peripheral Neurons, Muscles, and Other Cells
AID  - 10.1523/JNEUROSCI.18-08-02991.1998
DP  - 1998 Apr 15
TA  - The Journal of Neuroscience
PG  - 2991--3002
VI  - 18
IP  - 8
4099  - http://www.jneurosci.org/content/18/8/2991.short
4100  - http://www.jneurosci.org/content/18/8/2991.full
SO  - J. Neurosci.1998 Apr 15; 18
AB  - Receptor protein tyrosine phosphatases (rPTPs) are thought to play a crucial role in neuronal development, particularly in pathfinding by growing processes. We have cloned and sequenced two Hirudo medicinalis rPTPs that are homologous to theDrosophila and vertebrate rPTPs of the Leukocyte common antigen-related (LAR) subfamily. These Hirudo rPTPs, HmLAR1 and HmLAR2, are products of different, homologous genes, both containing two tandem intracellular phosphatase domains and ectodomains with three tandem Ig domains and different numbers of tandem fibronectin type III (FIII) domains. They are expressed in distinct patterns during embryogenesis. HmLAR1 mRNA is expressed by a subset of central and peripheral neurons and by several peripheral muscular structures, whereas HmLAR2 mRNA is expressed by a different subset of central neurons and by the peripheral, neuron-like Comb cells. HmLAR1 and HmLAR2 proteins are located on the neurites of central neurons. In addition, HmLAR2 is expressed on the cell body, processes, and growth cones of the Comb cells. Because of their CAM-like ectodomains and homology to proteins known to be involved in pathfinding and because they are expressed by different subsets of neurons, we hypothesize that HmLAR1 and HmLAR2 participate in navigational decisions that distinguish the sets of neurons that express them. Furthermore, we hypothesize that HmLAR2 is also involved in setting up the highly regular array of parallel processes established by the Comb cells. Lastly, we propose that the HmLAR1 ectodomain on peripheral muscle cells plays a role in target recognition via interactions with neuronal receptors, which might include HmLAR1 or HmLAR2.