scholarly journals Regulation of CNS and motor axon guidance in Drosophila by the receptor tyrosine phosphatase DPTP52F

Development ◽  
2001 ◽  
Vol 128 (21) ◽  
pp. 4371-4382 ◽  
Author(s):  
Benno Schindelholz ◽  
Matthias Knirr ◽  
Rahul Warrior ◽  
Kai Zinn
Keyword(s):  
Axon Guidance ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatases ◽  
Genomic Analysis ◽  
Motor Axon ◽  
Phosphatase Domain ◽  
C Elegans ◽  
Fibronectin Type Iii ◽  
Motor Nerves ◽  
Receptor Tyrosine Phosphatase

Receptor-linked protein tyrosine phosphatases (RPTPs) regulate axon guidance and synaptogenesis in Drosophila embryos and larvae. We describe DPTP52F, the sixth RPTP to be discovered in Drosophila. Our genomic analysis indicates that there are likely to be no additional RPTPs encoded in the fly genome. Five of the six Drosophila RPTPs have C. elegans counterparts, and three of the six are also orthologous to human RPTP subfamilies. DPTP52F, however, has no clear orthologs in other organisms. The DPTP52F extracellular domain contains five fibronectin type III repeats and it has a single phosphatase domain. DPTP52F is selectively expressed in the CNS of late embryos, as are DPTP10D, DLAR, DPTP69D and DPTP99A. To define developmental roles of DPTP52F, we used RNA interference (RNAi)-induced phenotypes as a guide to identify Ptp52F alleles among a collection of EMS-induced lethal mutations. Ptp52F single mutant embryos have axon guidance phenotypes that affect CNS longitudinal tracts. This phenotype is suppressed in Dlar Ptp52F double mutants, indicating that DPTP52F and DLAR interact competitively in regulating CNS axon guidance decisions. Ptp52F single mutations also cause motor axon phenotypes that selectively affect the SNa nerve. DPTP52F, DPTP10D and DPTP69D have partially redundant roles in regulation of guidance decisions made by axons within the ISN and ISNb motor nerves.

scholarly journals A novel receptor-type protein tyrosine phosphatase with a single catalytic domain is specifically expressed in mouse brain

1995 ◽  
Vol 305 (2) ◽  
pp. 499-504 ◽  
Author(s):  
W Hendriks ◽  
J Schepens ◽  
C Brugman ◽  
P Zeeuwen ◽  
B Wieringa
Keyword(s):  
Mouse Brain ◽  
Tyrosine Kinases ◽  
Catalytic Domain ◽  
Tyrosine Phosphatase ◽  
Cell Signalling ◽  
Protein Tyrosine Phosphatases ◽  
Pcr Amplification ◽  
Phosphatase Domain ◽  
Protein Tyrosine ◽  
The Brain

Protein tyrosine phosphatases (PTPases) are important regulatory proteins that, together with protein tyrosine kinases, determine the phosphotyrosine levels in cell signalling proteins. By PCR amplification of mouse brain cDNA fragments encoding the catalytic domains of these enzymes, we identified three novel members of the PTPase gene family. Northern-blot analysis showed that two of these novel clones represent brain-specific PTPases, whereas the third originates from a large-sized mRNA that is more ubiquitously expressed. A full-length cDNA encoding one of the brain-specific PTPases, PTP-SL, was isolated. Sequence analysis revealed a transmembrane PTPase containing a single catalytic phosphatase domain that has 45% homology to a rat cytoplasmic brain-specific PTPase named STEP. This suggests a role for PTP-SL in cell-cell signalling processes in the brain.

Receptor tyrosine phosphatase R-PTP-kappa mediates homophilic binding

1994 ◽  
Vol 14 (1) ◽  
pp. 1-9
Author(s):  
J Sap ◽  
Y P Jiang ◽  
D Friedlander ◽  
M Grumet ◽  
J Schlessinger
Keyword(s):  
Tyrosine Phosphatase ◽  
Extracellular Domain ◽  
Cell Contact ◽  
Intercellular Interaction ◽  
Homophilic Binding ◽  
Fibronectin Type Iii ◽  
Immunoglobulin Domain ◽  
Receptor Tyrosine Phosphatases ◽  
Receptor Tyrosine Phosphatase ◽  
Cellular Aggregates

Receptor tyrosine phosphatases (R-PTPases) feature PTPase domains in the context of a receptor-like transmembrane topology. The R-PTPase R-PTP-kappa displays an extracellular domain composed of fibronectin type III motifs, a single immunoglobulin domain, as well as a recently defined MAM domain (Y.-P. Jiang, H. Wang, P. D'Eustachio, J.M. Musacchio, J. Schlessinger, and J. Sap, Mol. Cell. Biol. 13:2942-2951, 1993). We report here that R-PTP-kappa can mediate homophilic intercellular interaction. Inducible expression of the R-PTP-kappa protein in heterologous cells results in formation of stable cellular aggregates strictly consisting of R-PTP-kappa-expressing cells. Moreover, the purified extracellular domain of R-PTP-kappa functions as a substrate for adhesion by cells expressing R-PTP-kappa and induces aggregation of coated synthetic beads. R-PTP-kappa-mediated intercellular adhesion does not require PTPase activity or posttranslational proteolytic cleavage of the R-PTP-kappa protein and is calcium independent. The results suggest that R-PTPases may provide a link between cell-cell contact and cellular signaling events involving tyrosine phosphorylation.

scholarly journals The Cell Surface Receptor Tartan Is a Potential In Vivo Substrate for the Receptor Tyrosine Phosphatase Ptp52F

2009 ◽  
Vol 29 (12) ◽  
pp. 3390-3400 ◽  
Author(s):  
Lakshmi Bugga ◽  
Anuradha Ratnaparkhi ◽  
Kai Zinn
Keyword(s):  
Cell Surface ◽  
Axon Guidance ◽  
Motor Nerve ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatases ◽  
Cell Surface Receptor ◽  
Wild Type ◽  
Surface Receptor

ABSTRACT Receptor-linked protein-tyrosine phosphatases (RPTPs) are essential regulators of axon guidance and synaptogenesis in Drosophila, but the signaling pathways in which they function are poorly defined. We identified the cell surface receptor Tartan (Trn) as a candidate substrate for the neuronal RPTP Ptp52F by using a modified two-hybrid screen with a substrate-trapping mutant of Ptp52F as “bait.” Trn can bind to the Ptp52F substrate-trapping mutant in transfected Drosophila S2 cells if v-Src kinase, which phosphorylates Trn, is also expressed. Coexpression of wild-type Ptp52F causes dephosphorylation of v-Src-phosphorylated Trn. To examine the specificity of the interaction in vitro, we incubated Ptp52F-glutathione S-transferase (GST) fusion proteins with pervanadate-treated S2 cell lysates. Wild-type Ptp52F dephosphorylated Trn, as well as most other bands in the lysate. GST “pulldown” experiments demonstrated that the Ptp52F substrate-trapping mutant binds exclusively to phospho-Trn. Wild-type Ptp52F pulled down dephosphorylated Trn, suggesting that it forms a stable Ptp52F-Trn complex that persists after substrate dephosphorylation. To evaluate whether Trn and Ptp52F are part of the same pathway in vivo, we examined motor axon guidance in mutant embryos. trn and Ptp52F mutations produce identical phenotypes affecting the SNa motor nerve. The genes also display dosage-dependent interactions, suggesting that Ptp52F regulates Trn signaling in SNa motor neurons.

The specificity of motor innervation of the chick wing does not depend upon the segmental origin of muscles

Development ◽  
1987 ◽  
Vol 99 (4) ◽  
pp. 565-575 ◽  
Author(s):  
R.J. Keynes ◽  
R.V. Stirling ◽  
C.D. Stern ◽  
D. Summerbell
Keyword(s):  
Spinal Cord ◽  
Axon Guidance ◽  
Neural Tube ◽  
Muscle Cells ◽  
Motor Axon ◽  
Motor Innervation ◽  
Motor Nerves ◽  
Vertebrate Embryos ◽  
Nerve Muscle ◽  
Somitic Mesoderm

In vertebrate embryos, motor axons originating from a particular craniocaudal position in the neural tube innervate limb muscles derived from myoblasts of the same segmental level. We have investigated whether this relationship is important for the formation of specific nerve-muscle connections, by altering the segmental origin of muscles and examining their resulting innervation. First, by grafting quail wing somites to a new craniocaudal position opposite the chick wing, we established that the segmental origin of a muscle can be altered: presumptive muscle cells migrated according to their new, rather than their original, somitic level, colonizing a different subset of muscles. However, after reversal of a length of brachial somitic mesoderm along the craniocaudal axis, or exchange or shift of brachial somites, the craniocaudal position of wing muscle motoneurone pools within the spinal cord was undisturbed, despite the new segmental origin of the muscles themselves. While not excluding the possibility that muscles and their motor nerves are labelled segmentally, we conclude that specific motor axon guidance in the wing does not depend upon the existence of such labels.

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