Neuronal co-localization of different isoforms of tachykinin-related peptides (LemTRPs) in the cockroach brain.
Seven isoforms of tachykinin-related peptides (TRPs) have been isolated from the brain of the cockroach Leucophaea maderae. These peptides (LemTRP-1, 2, and 5-9) share the C-terminal sequence GFX(1)GX(2)Ramide (where X(1) and X(2) are variable residues). In order to determine the neuronal distribution of several of these LemTRP isoforms, we raised antisera to their variable N-termini. Antisera to LemTRP-1, 2, 3, 7, and 8 were utilized for immunocytochemistry on cryostat sections of the L. maderae brain. As expected, the gut peptide LemTRP-3 was not detected in the brain, and the antisera to LemTRP-1, 2, and 7 labeled the same sets of neurons in different regions of the brain. These neurons could also be labeled with antisera raised to the more conserved C-termini of LemTRP-1 and the locust TRP LomTK-I. The antiserum to LemTRP-8 predominantly labeled a set of neurons distinct from that seen with any other N- or C-terminus-directed antisera, suggesting that it recognizes epitope(s) other than known insect TRPs. Our findings indicate that at least three of the LemTRPs are always co-localized in neurons of the L. maderae brain. We have also been able to show that LemTRP-2, which is an N-terminally extended form (17-mere) of LemTRP-1 with a dibasic putative cleavage site, is transported throughout the processes of the neurons in the same manner as LemTRP-1 and 7. Thus, LemTRP-2 may be released with the other shorter LemTRPs. This is the first investigation of LemTRP distribution in the cockroach central nervous system utilizing antisera to native peptides.
Nässel
Dick R
DR
Department of Zoology, Stockholm University, 10691 Stockholm, Sweden. dnassel@zoologi.su.se
Winther
Asa M E
AM
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000166:cytology; D001923:Brain Chemistry / Q000502:physiology*; D003058:Cockroaches / Q000378:metabolism*; D005260:Female; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D019476:Insect Proteins / Q000378:metabolism*; D007536:Isomerism; D008297:Male; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D015320:Tachykinins / Q000378:metabolism*
D019476:Insect Proteins; C114445:LemTRP-1 protein, Leucophaea maderae; D015320:Tachykinins