Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.4.24.59 (
MIP
)
4,906
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A new member of the aquaporin (AQP) family has been identified from rat testis. This gene, referred as
aquaporin 7
(
AQP7
), encodes a 269-amino acid protein that contained the conserved NPA motifs of
MIP
family proteins.
AQP7
has the amino acid sequence homology with other aquaporins ( approximately 30%), and it is highest with AQP3 (48%), suggesting that both AQP3 and
AQP7
belong to a subfamily in the
MIP
family. Injection of
AQP7
-cRNA into Xenopus oocytes expressed a 26-kDa protein detected by immunoblotting. The expression of
AQP7
in oocytes stimulated the osmotic water permeability by 10-fold which was not inhibited by 0.3 mM mercury chloride. The Arrhenius activation energy for the stimulated water permeability was low (2.1 kcal/mol).
AQP7
also facilitated glycerol and urea transport by 5- and 9-fold, respectively. The activation energy for glycerol was also low (5.3 kcal/mol after the correction of the endogenous glycerol permeability of oocytes). Northern blot analysis revealed a 1.5-kilobase pair transcript expressed abundantly in testis. In situ hybridization of testis revealed the expression of
AQP7
at late spermatids in seminiferous tubules. The immunohistochemistry of testis localized the
AQP7
expression at late spermatids and at maturing sperms.
AQP7
may play an important role in sperm function.
...
PMID:Cloning and functional expression of a new water channel abundantly expressed in the testis permeable to water, glycerol, and urea. 925 1
