bep1

Function

bep1 is a member of a multigenic family, coding for butanol-extractable proteins.
In sea urchin embryos butanol treatment extracts cell surface proteins including the constituents of a 22S particle called toposome, which is believed to play a role in cell interactions.
bep1 is a single-copy gene (Di Carlo et al., 1990).

Protein

bep1 is a butanol-extractable protein.
bep1 contain open reading frame coding for 295 amino acids.
Within the coding region there are two domains (A and B) and one specific central region. The A region code for 68 aa, the B part contain 106 amino acids, the specific region can codify for 97 amino acids.
By amino acid analysis it is possible to observe that A and B regions are hydrophobic. Moreover, the presence of two Cys in both of these regions allows to suppose that the two parts might interact and build a highly hydrophobic zone to be anchored at the plasma membrane to the interaction between both parts (Di Carlo et al., 1990).
GenBank: 321050

Subcellular location

bep1 belongs to cell surface proteins (Di Carlo et al., 1990).

Expression Pattern

Nothern blot analysis showed that bep1 is transcribed during oogenesis into mRNA of 1.4 kb, which is stored in egg and utilized during early embryogenesis. The highest intensity of the band is observed in ovary and in egg RNA. The signal reduction is observed from 32 cell stage.
This RNA is not detectable after the gastrula stage (Di Carlo et al., 1990).
bep1 maternal messenger is localized in the animal part of P. lividus egg and embryos. It was demonstrated that bep1 mRNA is associated with the cytoskeleton element and that this association is necessary for the localization (Romancino et al., unpublished results).
The spatial distribution of bep1 protein in eggs and embryos was established by whole mount immunohistochemistry. This protein is located in the animal part of unfertilized and fertilized eggs; thereafter it is much less represented in structures derived from the vegetal cells of the embryo such as the micromeres of the 16 cell stage, the primary mesenchyme of blastula and the gut of gastrula. At the prism stage bep1 protein is present to some ectodermal parts and thereafter, at the pluteus stage, to the oral region (Romancino et al., 1998).

mRNA level

Temporal accumulation
Method: Nothern blot analysis
Reference: Di Carlo et al., 1990

Stage	Egg	32 cells	Morula	Blastula	Gastrula	Prism	Pluteus
Level	+ +	+ +	+	+	+ -	-	-

Sequences

GenBank

Regulatory Regions

Regions

Regulatory Connections

Upstream Genes

LP54 (54-kDa protein)
bep1

Downstream Genes

Evolutionary Homologues

Links

Urchin Web

Bibliography

UrchiNet

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