Anthrax Pathway
Home



The pathway of the anthrax toxin can be described in three different steps: Entry into the cell, the actions of OF, and the actions of LF. Although it is known that these are the three main steps, there a still many unanswered questions as to how exactly this pathway proceeds.

Background
Anthrax Structure

The first step of the Anthrax pathway is the uptake of the toxin into the cell. The uptake of LeTx into the cell first involves the binding of PA to an unknown ATR. Through some type of furin-like protease activation, PA undergoes a significant conformational change. After this change, both EF and LF bind very tightly to PA, and the whole system is brought into the cell via receptor-mediated endocytosis (Lacy et all, 2002). Once inside the cell, LF and EF are released from PA, and begin their separate pathways.

MAPK Structure
Anthrax Pathway
MAPK Cascade
Lethal Factor and MAPK
The Future
References

Once inside the cell the LF is unbound from PA. The target of LF is the second step in the cascade of MAPK. LF attacks MAPKK in a still largely unknown manner. What is known is that LF attacks almost the entire family of MAPKK; MKK4, MKK6 and MKK7, at the N-terminal. However, LF does not attack MKK5. A reason for this could be the very distant relationship this MAPKK has with teh rest of its family, as can be seen in figure ? In addition to the MAPKK, LF also attacks MKK4, MKK6 and MKK7. Because of its broad specificity, LF is thought to interact with specific structural motifs to recognize its substrate and act at full enzyme activity (Vitale et all, 2000).

Figure ??--The MAPKK family