Difference between revisions of "Phosphatase Subfamily PPIP5K"

From PhosphataseWiki
Jump to: navigation, search
(Evolution)
Line 1: Line 1:
 
[[Phosphatase classification|Phosphatase Classification]]: [[Phosphatase_Fold_HP|Fold HP]]: [[Phosphatase_Superfamily_HP|Superfamily HP]] (histidine phosphatase): [[Phosphatase_Family_HP2|Family HP, branch 2]]: [[Phosphatase_Subfamily_PPIP5K|PPIP5K]]
 
[[Phosphatase classification|Phosphatase Classification]]: [[Phosphatase_Fold_HP|Fold HP]]: [[Phosphatase_Superfamily_HP|Superfamily HP]] (histidine phosphatase): [[Phosphatase_Family_HP2|Family HP, branch 2]]: [[Phosphatase_Subfamily_PPIP5K|PPIP5K]]
  
 +
PPIP5K has a pseudophosphatase domain which bind to PtdIns(3,4,5)P3 and a kinase domain of RimK superfamily. The proteins therefore show kinase activity which convert InsP6 and 5-InsP7 to 1-InsP7 and InsP8.
  
 
=== Evolution ===
 
=== Evolution ===
Line 6: Line 7:
  
 
=== Domain ===
 
=== Domain ===
PPIP5K has two domains: N-terminal RimK/ATP-grasp domain which encodes its kinase activity, and C-terminal HP2 domain <cite>fridy07</cite>. Unlike other members of HP2 family which are protein or non-protein phosphatases, the HP2 domain of PPIP5K is not catalytically active. Instead, this HP2 domain is specialized for binding PtdIns(3,4,5)P3, as a partial PH (pleckstrin homology) consensus sequence is spliced into this HP2 domain <cite>gokhale11</cite>.
+
PPIP5K has two domains: N-terminal RimK/ATP-grasp domain, and C-terminal HP2 domain <cite>fridy07</cite>.  
  
=== Functions ===
+
RimK/ATP-grasp domain confer PPIP5K's kinase activity that converts InsP6 and 5-InsP7 to 1-InsP7 and InsP8 <cite>fridy07, choi07</cite>.
Human PPIP5K1 and PPIP5K2 mediates phosphorylation of InsP6 and 5-InsP7 to 1-InsP7 and InsP8, which are multifunctional signaling molecules that regulate diverse cellular activities <cite>fridy07, choi07</cite>.
+
 
 +
Unlike other members of HP2 family which are protein or non-protein phosphatases, the HP2 domain of PPIP5K is not catalytically active. Instead, this HP2 domain is specialized for binding PtdIns(3,4,5)P3, as a partial PH (pleckstrin homology) consensus sequence is spliced into this HP2 domain <cite>gokhale13</cite>.
 +
 
 +
=== Catalytic activity and functions ===
 +
As mentioned above, the phosphatase domain of PPIP5K, HP2 domain, is catalytically inactive <cite>gokhale13</cite>. Because the kinase domain is active, the proteins show kinase activity in general. In particular, human PPIP5K1 and PPIP5K2 mediates phosphorylation of InsP6 and 5-InsP7 to 1-InsP7 and InsP8. InsP7 and InsP8 are multifunctional signaling molecules that regulate diverse cellular activities <cite>fridy07, choi07</cite>.
 +
 
 +
=== References ===
 +
<biblio>
 +
#fridy07 pmid=17690096
 +
#choi07 pmid=17702752
 +
#gokhale13 pmid=23682967
 +
</biblio>

Revision as of 03:56, 2 January 2015

Phosphatase Classification: Fold HP: Superfamily HP (histidine phosphatase): Family HP, branch 2: PPIP5K

PPIP5K has a pseudophosphatase domain which bind to PtdIns(3,4,5)P3 and a kinase domain of RimK superfamily. The proteins therefore show kinase activity which convert InsP6 and 5-InsP7 to 1-InsP7 and InsP8.

Evolution

PPIP5K is conserved across opisthokont. Human genome has three copies.

Domain

PPIP5K has two domains: N-terminal RimK/ATP-grasp domain, and C-terminal HP2 domain [1].

RimK/ATP-grasp domain confer PPIP5K's kinase activity that converts InsP6 and 5-InsP7 to 1-InsP7 and InsP8 [1, 2].

Unlike other members of HP2 family which are protein or non-protein phosphatases, the HP2 domain of PPIP5K is not catalytically active. Instead, this HP2 domain is specialized for binding PtdIns(3,4,5)P3, as a partial PH (pleckstrin homology) consensus sequence is spliced into this HP2 domain [3].

Catalytic activity and functions

As mentioned above, the phosphatase domain of PPIP5K, HP2 domain, is catalytically inactive [3]. Because the kinase domain is active, the proteins show kinase activity in general. In particular, human PPIP5K1 and PPIP5K2 mediates phosphorylation of InsP6 and 5-InsP7 to 1-InsP7 and InsP8. InsP7 and InsP8 are multifunctional signaling molecules that regulate diverse cellular activities [1, 2].

References

Error fetching PMID 17690096:
Error fetching PMID 17702752:
Error fetching PMID 23682967:
  1. Error fetching PMID 17690096: [fridy07]
  2. Error fetching PMID 17702752: [choi07]
  3. Error fetching PMID 23682967: [gokhale13]
All Medline abstracts: PubMed | HubMed