Pregnancy-associated plasma protein-A (PAPP-A) modulates early developmental rate in zebrafish independent of its proteolytic activity

TY - JOUR

T1 - Pregnancy-associated plasma protein-A (PAPP-A) modulates early developmental rate in zebrafish independent of its proteolytic activity

AU - Kjær-Sørensen, Kasper

AU - Engholm, Ditte Høyer

AU - Kamei, Hiroyasu

AU - Mørch, Maria Grymer Metz

AU - Kristensen, Anisette O

AU - Zhou, Jianfeng

AU - Conover, Cheryl A.

AU - Duan, Cunming

AU - Oxvig, Claus

PY - 2013/4

Y1 - 2013/4

N2 - Pregnancy-associated plasma protein-A (PAPP-A) is a large metalloproteinase specifically cleaving IGF binding proteins, causing increased IGF bioavailability and hence local regulation of IGF receptor activation. We have identified two highly conserved zebrafish homologs of the human PAPP-A gene. Expression of zebrafish Papp-a, one of the two paralogs, begins during gastrulation and persists throughout the first week of development, and analyses demonstrate highly conserved patterns of expression between adult zebrafish, humans, and mice. We show that the specific knockdown of zebrafish papp-a limits the developmental rate beginning during gastrulation without affecting the normal patterning of the embryo. This phenotype is different from those resulting from deficiency of Igf receptor or ligand in zebrafish, suggesting a function of Papp-a outside the Igf system. Biochemical analysis of recombinant zebrafish Papp-a demonstrates conservation of proteolytic activity, specificity, and intrinsic regulatory mechanism. However, in vitro transcribed mRNA, which encodes a proteolytically inactive Papp-a mutant, recues the papp-a knockdown phenotype as efficient as wild-type Papp-a. Thus, the developmental phenotype of papp-a knockdown is not a consequence of lacking Papp-a proteolytic activity. We conclude that Papp-a possesses biological functions independent of its proteolytic activity. Our data represent the first evidence for a non-proteolytic function of PAPP-A.

AB - Pregnancy-associated plasma protein-A (PAPP-A) is a large metalloproteinase specifically cleaving IGF binding proteins, causing increased IGF bioavailability and hence local regulation of IGF receptor activation. We have identified two highly conserved zebrafish homologs of the human PAPP-A gene. Expression of zebrafish Papp-a, one of the two paralogs, begins during gastrulation and persists throughout the first week of development, and analyses demonstrate highly conserved patterns of expression between adult zebrafish, humans, and mice. We show that the specific knockdown of zebrafish papp-a limits the developmental rate beginning during gastrulation without affecting the normal patterning of the embryo. This phenotype is different from those resulting from deficiency of Igf receptor or ligand in zebrafish, suggesting a function of Papp-a outside the Igf system. Biochemical analysis of recombinant zebrafish Papp-a demonstrates conservation of proteolytic activity, specificity, and intrinsic regulatory mechanism. However, in vitro transcribed mRNA, which encodes a proteolytically inactive Papp-a mutant, recues the papp-a knockdown phenotype as efficient as wild-type Papp-a. Thus, the developmental phenotype of papp-a knockdown is not a consequence of lacking Papp-a proteolytic activity. We conclude that Papp-a possesses biological functions independent of its proteolytic activity. Our data represent the first evidence for a non-proteolytic function of PAPP-A.

KW - zebrafisk

KW - PAPP-A

KW - proteolyse

U2 - 10.1074/jbc.M112.426304

DO - 10.1074/jbc.M112.426304

M3 - Journal article

C2 - 23430244

SN - 0021-9258

VL - 288

SP - 9982

EP - 9992

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

ER -