Corp. Code, § 13408

The following shall be grounds for the suspension or revocation of the certificate of registration of a professional corporation or a foreign professional corporation qualified to render professional services in this state: (a) if all shareholders who are licensed persons of such corporation shall at any one time become disqualified persons, or (b) if the sole shareholder shall become a disqualified person, or (c) if such corporation shall knowingly employ or retain in its employment a disqualified person, or (d) if such corporation shall violate any applicable rule or regulation adopted by the governmental agency regulating the profession in which such corporation is engaged, or (e) if such corporation shall violate any statute applicable to a professional corporation or to a foreign professional corporation, or (f) any ground for such suspension or revocation specified in the Business and Professions Code relating to the profession in which such corporation is engaged. In the event of such suspension or revocation of its certificate of registration such corporation shall cease forthwith to render professional services in this state.