Avtor/Urednik     Rupnik, M; Law, GJ; Mason, WT; Zorec, R
Naslov     Mastoparan and Rab3AL peptide potentiation of calcium-independent secretory activity in rat melanotrophs is inhibited by GDPbetaS
Tip     članek
Vir     FEBS Lett
Vol. in št.     Letnik 411, št. 2-3
Leto izdaje     1997
Obseg     str. 356-8
Jezik     eng
Abstrakt     The whole-cell patch-clamp membrane capacitance measurement was used to monitor secretory activity in rat melanotrophs, while rab3AL, putative effector domain peptides of Rb3 small GTPases (20-30 kDa), were introduced into cytosol. In melanotrophs dialyzed with calcium free solutions membrane capacitance tends to decrease slightly. This decrease is further potenciated with GDP beta S (500 micro M). We found that rab3AL (100 micro M) stimulated secretory activity in the absence of calcium. The rab3AL response was qualitatively comparable to the response to mastoparan (1 micro M), an activator of certain heterotrimeric GTP-binding proteins. Interestingly, inclusion of GDP beta S (500 micro M) resulted in a blockade of both rab3AL and mastoparan induced responses. We conclude that rab3AL and mastoparan induce calcium-independent stimulation of secretory activity in rat melanotrophs by activation of a downstream heterotrimeric GTP-binding protein.
Deskriptorji     G-PROTEINS
PITUITARY GLAND
WASP VENOMS
CALCIUM
AMINO ACID SEQUENCE
RATS
CELLS, CULTURED
GUANOSINE DIPHOSPHATE
PATCH-CLAMP TECHNIQUES
PEPTIDES
THIONUCLEOTIDES