PMID- 9013548
OWN - NLM
STAT- MEDLINE
DCOM- 19970402
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 272
IP  - 6
DP  - 1997 Feb 7
TI  - Unveiling the substrate specificity of meprin beta on the basis of the site in 
      protein kinase A cleaved by the kinase splitting membranal proteinase.
PG  - 3153-60
AB  - The kinase splitting membranal proteinase (KSMP) is a metalloendopeptidase that 
      inactivates the catalytic (C) subunit of protein kinase A (PKA) by clipping off 
      its carboxyl terminal tail. Here we show that this cleavage occurs at 
      Glu332-Glu333, within the cluster of acidic amino acids (Asp328-Glu334) of the 
      kinase. The Km values of KSMP and of meprin beta (which reproduces KSMP activity) 
      for the C-subunit are below 1 microM. The Km for peptides containing a stretch of 
      four Glu residues are in the micromolar range, illustrating the significant 
      contribution of this cluster to the substrate recognition of meprin beta. This 
      conclusion is supported by a systematic study using a series of the C-subunit 
      mutants with deletions and mutations in the cluster of acidics. Hydrophobic amino 
      acids vicinal to the cleavage site increase the Kcat of the proteinase. These 
      studies unveil a new specificity for meprin beta, suggesting new substrates that 
      are 1-2 orders of magnitude better in their Km and Kcat than those commonly used 
      for meprin assay. A search for substrates having such a cluster of acidics and 
      hydrophobics, which are accessible to meprin under physiological conditions, 
      point at gastrin as a potential target. Indeed, meprin beta is shown to cleave 
      gastrin at its cluster of five glutamic acid residues and also at the M-D bond 
      within its WMDF-NH2 sequence, which is indispensable for all the known biological 
      activities of gastrins. The latter meprin cleavage will lead to the inactivation 
      of gastrin and thus to the control of its activity.
FAU - Chestukhin, A
AU  - Chestukhin A
AD  - Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, 
      76100, Israel.
FAU - Litovchick, L
AU  - Litovchick L
FAU - Muradov, K
AU  - Muradov K
FAU - Batkin, M
AU  - Batkin M
FAU - Shaltiel, S
AU  - Shaltiel S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - EC 2.7.11.11 (Cyclic AMP-Dependent Protein Kinases)
RN  - EC 3.4.- (Endopeptidases)
RN  - EC 3.4.24.- (Metalloendopeptidases)
RN  - EC 3.4.24.63 (meprin B)
RN  - EC 3.4.99.- (kinase-splitting membranal proteinase)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - Cyclic AMP-Dependent Protein Kinases/*metabolism
MH  - Endopeptidases/*metabolism
MH  - Humans
MH  - Kinetics
MH  - Metalloendopeptidases/*metabolism
MH  - Molecular Sequence Data
MH  - Mutagenesis, Site-Directed
MH  - Peptide Mapping
MH  - Protein Conformation
MH  - Rabbits
MH  - Rats
MH  - Sequence Alignment
MH  - Sequence Deletion
MH  - Substrate Specificity
EDAT- 1997/02/07 00:00
MHDA- 1997/02/07 00:01
CRDT- 1997/02/07 00:00
PHST- 1997/02/07 00:00 [pubmed]
PHST- 1997/02/07 00:01 [medline]
PHST- 1997/02/07 00:00 [entrez]
AID - S0021-9258(19)78359-8 [pii]
AID - 10.1074/jbc.272.6.3153 [doi]
PST - ppublish
SO  - J Biol Chem. 1997 Feb 7;272(6):3153-60. doi: 10.1074/jbc.272.6.3153.