MTB1

Function

The metallothionein (MT) gene family in S. purpuratus consists of six or seven MT genes, four of these genes form an MTB subset.
The metallothionein-B genes code for a MT isoform distinguishable from the MTA isoform.
The MTB1 and MTA genes have a high degree of identity but diverge in structural detail and expression (Nemer et al., 1991).

Protein

Metallothioneins are small, cysteine-rich proteins comprised largely of heavy metal-binding domains (Nemer et al., 1991).
SWISS_PROT: Q27287

Subcellular location

Expression Pattern

The accumulation of MTB1 transcripts begins at 10-12h blastula stage.
The 0.9 kb MTB1 mRNA is found in both mesoendodermal and ectodermal tissue fractions, but more prominently in the mesoendodermal than ectodermal fraction. Heavy metal ion induction increases the expression of MTB1 mRNA with a higher level in the ectoderm than mesoendoderm.
In situ hybridization revealed that the MTB1 transcripts are present at a high level in both embryonic gut and oral ectoderm of pluteus larvae and at a low level in aboral ectoderm (Nemer et al., 1991).

mRNA level

Temporal accumulation
Method: Northern blot analysis
Reference: Nemer et al., 1991

Hours post fertilization 0 6 9 12 15 18 21

Level (transcripts per embryo X 10^-5) 0,003 0,003 0,003 0,003 0,01 0,013 0,018