| Symbol: rho
|
Flybase ID: {Flybase_ID} |
| Synonyms: veinlet
(ve)
|
{GadFly} |
| Function: provein
gene |
{LocusLink} |
| Keywords: {Keywords} |
{Interactive_Fly} |
- serine protease - transmembrane protein involved with Epidermal growth
factor receptor signaling - required for the processing of Spitz, the
Egfr ligand.
|
- Regulates the cleavage of Spitz and turns it into a soluble active
ligand of Egfr (Schweitzer et al., 1995)
- Rhom contributes to the formation of denticle types 1-4 (Wiellette,
1999)
|
- Collier/Knot
- In col1 mutant discs, two types of changes are
observed: first, whereas rho is only expressed in a few cells in
the dorsal presumptive L4 vein, it is expressed in two to four rows
of cells, rather than a single one, in the presumptive L3 vein (Fig.
4B). Second, the distance separating the L3 and residual L4 veins
is reduced (Fig. 4B), suggesting a posterior shift, in addition
to widening, of the presumptive L3m vein, compared with L3. (Crozatier,
2002)
- In col1 mutant discs, the L3m rho and
col expression domains partially overlapped, confirming that
the position of L3m vein has been shifted posteriorwards by several
cell diameters relative to wild type (Fig. 4C,D), as previously
deduced from Ci labelling of 24 hours APF pupae (Fig. 2D). However,
rho labelling did not abut the AP boundary, indicating that rho
transcription remained repressed in the anterior cells, which express
En (Blair, 1992) (Fig.4I) (Crozatier,
2002)
- Spitz
- Since Veinlet (rhom) activates Spitz and since Spitz is expressed
everywhere (Rutledge et al., 1992), the stripes of veinlet (rhom)
expression are believed to be a source of active Spitz.
- Wingless
- rhomboid expression is abolished by continuous and uniform
expression of Wingless (using the transgene combination arm-Gal4/UAS-wg).
Also delayed addition of Wingless up to mid-stage 11 with UAS-winglessts
also wipes out rhomboid expression. Later ectopic expression,
induced at late stage 11, inhibits rhomboid transcription only in
the midventral region (Fig 3C), and if sibling embryos are left
to develop, they make ectopic naked cuticle in the same region (Figure
3D) (Sanson,
1999)
- Since rho activates Spitz and since Spitz is expressed everywhere
the stripes of rho expression are believed to be a source of active
Spitz
- contributes to the formation of denticle types 1-4
|
- Wg signaling represses rho expression (Sanson et al., 1999; Gritzan
et al ., 1999)
- Hh and Serrate both contribute positively to rho expression while
Serrate is negatively regulated by both Hh and Wg (Alexandre,
1999)
|
- Embryo
- In the ventral ectoderm of late embryos, veinlet is expressed
in stripes at the posterior of the en domain, a region due to make
denticles (Bier, 1990; O'Keefe, 1997; Szüts, 1997)
- rhomboid is expressed in the cells secreting rows 2-4 (Fig 4B)
(Sanson,
1999)
- Wing imaginal discs
- Expressed in the primordia of all the longitudial veins at the
end of the 3rd larval instar, as well as in two stripes flanking
the presumptive wing margin (Sturtevant,
1995)
- In wild-type third instar imaginal discs, rho-expressing
cells flanked the col expression domain on both sides, with
one to two rows of intercalary cells expressing neither gene (Fig.
4C). (Crozatier,
2002)
|
- Large protein family conserved from bacteria to man: novel family
of proteases likely to be involved in a variety of different processes
- Drosophila itself has seven different Rhomboid-like proteins, three
of which (Rhomboid-1, Rhomboid-2 and Rhomboid-3) have been associated
with EGF receptor signalling (Wasserman, J.D. et al. 2000; Guichard,
A. et al. 2000)
|