Ht31: the first protein kinase A anchoring protein to integrate protein kinase A and Rho signaling

FEBS Lett. 2001 Nov 2;507(3):264-8. doi: 10.1016/s0014-5793(01)02995-7.


In an attempt to isolate protein kinase A anchoring proteins (AKAPs) involved in vasopressin-mediated water reabsorbtion, the complete sequence of the human AKAP Ht31 was determined and a partial cDNA of its rat orthologue (Rt31) was cloned. The Ht31 cDNA includes the estrogen receptor cofactor Brx and the RhoA GDP/GTP exchange factor proto-lymphoid blast crisis (Lbc) sequences. The Ht31 gene was assigned to chromosome 15 (region q24-q25). It encodes Ht31 and the smaller splice variants Brx and proto-Lbc. A protein of the predicted size of Ht31 (309 kDa) was detected in human mammary carcinoma and HeLa cells. Anti-Ht31/Rt31 antibodies immunoprecipitated RhoA from primary cultured rat renal inner medullary collecting duct cells, indicating an interaction between the AKAP and RhoA in vivo. These results suggest that Ht31/Rt31 represent a new type of AKAP, containing both an anchoring and a catalytic domain, which appears to be capable of modulating the activity of an interacting partner. Ht31/Rt31 have the potential to integrate Rho and protein kinase A signaling pathways, and thus, are prime candidates to regulate vasopressin-mediated water reabsorbtion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • A Kinase Anchor Proteins
  • Adaptor Proteins, Signal Transducing
  • Amino Acid Sequence
  • Animals
  • Cells, Cultured
  • Chromosomes, Human, Pair 15
  • Cloning, Molecular
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Guanine Nucleotide Exchange Factors / metabolism
  • HeLa Cells
  • Humans
  • Kidney Medulla / cytology
  • Minor Histocompatibility Antigens
  • Molecular Sequence Data
  • Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins / metabolism*
  • Rats
  • Signal Transduction
  • rhoA GTP-Binding Protein / metabolism*


  • A Kinase Anchor Proteins
  • AKAP13 protein, human
  • Adaptor Proteins, Signal Transducing
  • Guanine Nucleotide Exchange Factors
  • Minor Histocompatibility Antigens
  • Oncogene Proteins
  • Proto-Oncogene Proteins
  • Cyclic AMP-Dependent Protein Kinases
  • rhoA GTP-Binding Protein

Associated data

  • GENBANK/AF387101
  • GENBANK/AF387102