Maxadilan specifically interacts with PAC1 receptor, which is a dominant form of PACAP/VIP family receptors in cultured rat cortical neurons.
Maxadilan is a potent vasodilator peptide isolated from salivary gland extracts of the hematophagous sand fly. Recently, the possibility was demonstrated that maxadilan binds to PAC1 receptor (PACAP, pituitary adenylate cyclase activating polypeptide type I receptor) in mammals. In the present study, we demonstrated that: (1) maxadilan specifically binds to PAC1 receptor and stimulates cyclic AMP accumulation in a dose-dependent manner in CHO cells stably expressing PAC1 receptor, not VIP (vasoactive intestinal polypeptide) receptors; that (2) the deleted peptide (amino acid #24-42) of maxadilan (termed max.d.4) also specifically binds to PAC1 receptor although max.d.4 inhibits cyclic AMP accumulation stimulated by both maxadilan and PACAP; and that (3) max.d.4 completely blocks the cyclic AMP accumulation induced by VIP in cultured rat cortical neurons. The expression of specific PACAP receptors in cultured rat cortical neurons was further investigated by the reverse transcription-polymerase chain reaction technique, which showed the presence of mRNA coding for PAC1 receptor among PACAP/VIP family receptors. These data indicate that maxadilan and max.d.4 represent important tools for clarifying the physiological role of PAC1 receptor, and that PAC1 receptor plays an important role in the regulation of the functions induced by PACAP in rat cultured cortical neurons.
Tatsuno
I
I
The Second Department of Internal Medicine, Chiba University School of Medicine, 1-8-1 Inohana, Chuo-ku, 260-8670, Chiba-city, Japan. ichico@intmed02.m.chiba-u.ac.jp
Uchida
D
D
Tanaka
T
T
Saeki
N
N
Hirai
A
A
Saito
Y
Y
Moro
O
O
Tajima
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D016466:CHO Cells; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D019476:Insect Proteins / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D011979:Receptors, Pituitary Hormone / Q000096:biosynthesis / Q000187:drug effects*; D018005:Receptors, Vasoactive Intestinal Peptide / Q000096:biosynthesis / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism; D014665:Vasodilator Agents / Q000494:pharmacology*
C495403:Adcyap1 protein, rat; C495505:Adcyap1r1 protein, rat; D019476:Insect Proteins; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D012333:RNA, Messenger; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D011979:Receptors, Pituitary Hormone; D018005:Receptors, Vasoactive Intestinal Peptide; D014665:Vasodilator Agents; C069147:maxadilan protein, insect; D014660:Vasoactive Intestinal Peptide; D000242:Cyclic AMP